668123556 has 24 divisors (see below), whose sum is σ = 1559604480. Its totient is φ = 222615072.

The previous prime is 668123537. The next prime is 668123557. The reversal of 668123556 is 655321866.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (668123557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22390 + ... + 42866.

It is an arithmetic number, because the mean of its divisors is an integer number (64983520).

Almost surely, 2^668123556 is an apocalyptic number.

It is an amenable number.

668123556 is an abundant number, since it is smaller than the sum of its proper divisors (891480924).

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

668123556 is a wasteful number, since it uses less digits than its factorization.

668123556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23203 (or 23201 counting only the distinct ones).

The product of its digits is 259200, while the sum is 42.

The square root of 668123556 is about 25848.0861187052. The cubic root of 668123556 is about 874.2163567793.

The spelling of 668123556 in words is "six hundred sixty-eight million, one hundred twenty-three thousand, five hundred fifty-six".