669405600 has 288 divisors, whose sum is σ = 2564835840. Its totient is φ = 167915520.

The previous prime is 669405557. The next prime is 669405601. The reversal of 669405600 is 6504966.

It is a happy number.

669405600 is a `hidden beast` number, since 6 + 6 + 9 + 40 + 5 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×669405600² = 896207714622720000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669405601) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 366289 + ... + 368111.

It is an arithmetic number, because the mean of its divisors is an integer number (8905680).

Almost surely, 2^669405600 is an apocalyptic number.

669405600 is a gapful number since it is divisible by the number (60) 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 669405600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1282417920).

669405600 is an abundant number, since it is smaller than the sum of its proper divisors (1895430240).

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

669405600 is a wasteful number, since it uses less digits than its factorization.

669405600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869 (or 1850 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 669405600 is about 25872.8738256886. The cubic root of 669405600 is about 874.7751694458.

The spelling of 669405600 in words is "six hundred sixty-nine million, four hundred five thousand, six hundred".