997859478 has 64 divisors (see below), whose sum is σ = 2491711488. Its totient is φ = 258815520.

The previous prime is 997859477. The next prime is 997859543. The reversal of 997859478 is 874958799.

997859478 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997859477) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 501201 + ... + 503187.

It is an arithmetic number, because the mean of its divisors is an integer number (38932992).

Almost surely, 2^997859478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997859478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1245855744).

997859478 is an abundant number, since it is smaller than the sum of its proper divisors (1493852010).

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

997859478 is a wasteful number, since it uses less digits than its factorization.

997859478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3097.

The product of its digits is 45722880, while the sum is 66.

The square root of 997859478 is about 31588.9138464747. The cubic root of 997859478 is about 999.2859829677.

The spelling of 997859478 in words is "nine hundred ninety-seven million, eight hundred fifty-nine thousand, four hundred seventy-eight".