668988936 has 512 divisors, whose sum is σ = 2557440000. Its totient is φ = 156764160.

The previous prime is 668988857. The next prime is 668988977. The reversal of 668988936 is 639889866.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (26873856) is a multiple of the sum of its prime divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 9164196 + ... + 9164268.

It is an arithmetic number, because the mean of its divisors is an integer number (4995000).

Almost surely, 2^668988936 is an apocalyptic number.

668988936 is a gapful number since it is divisible by the number (66) 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 668988936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1278720000).

668988936 is an abundant number, since it is smaller than the sum of its proper divisors (1888451064).

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

668988936 is a wasteful number, since it uses less digits than its factorization.

668988936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 144 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 63.

The square root of 668988936 is about 25864.8204323943. The cubic root of 668988936 is about 874.5936337814.

The spelling of 668988936 in words is "six hundred sixty-eight million, nine hundred eighty-eight thousand, nine hundred thirty-six".