397638720 has 420 divisors, whose sum is σ = 1529631180. Its totient is φ = 97929216.

The previous prime is 397638713. The next prime is 397638727. The reversal of 397638720 is 27836793.

It is a happy number.

397638720 is a `hidden beast` number, since 3 + 9 + 7 + 638 + 7 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (397638713) and next prime (397638727).

It can be written as a sum of positive squares in 2 ways, for example, as 175509504 + 222129216 = 13248^2 + 14904^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397638727) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 13711666 + ... + 13711694.

It is an arithmetic number, because the mean of its divisors is an integer number (3641979).

Almost surely, 2^397638720 is an apocalyptic number.

397638720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 397638720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (764815590).

397638720 is an abundant number, since it is smaller than the sum of its proper divisors (1131992460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

397638720 is a wasteful number, since it uses less digits than its factorization.

397638720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 397638720 is about 19940.8806224800. The cubic root of 397638720 is about 735.3535991235.

The spelling of 397638720 in words is "three hundred ninety-seven million, six hundred thirty-eight thousand, seven hundred twenty".