668912634 has 128 divisors (see below), whose sum is σ = 1769402880. Its totient is φ = 185213952.

The previous prime is 668912633. The next prime is 668912659. The reversal of 668912634 is 436219866.

668912634 is a `hidden beast` number, since 6 + 6 + 8 + 9 + 1 + 2 + 634 = 666.

It is a super-2 number, since 2×668912634² = 894888223849635912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 668912634.

It is not an unprimeable number, because it can be changed into a prime (668912633) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 273264 + ... + 275700.

It is an arithmetic number, because the mean of its divisors is an integer number (13823460).

Almost surely, 2^668912634 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668912634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (884701440).

668912634 is an abundant number, since it is smaller than the sum of its proper divisors (1100490246).

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

668912634 is a wasteful number, since it uses less digits than its factorization.

668912634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2501 (or 2495 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 668912634 is about 25863.3453752603. The cubic root of 668912634 is about 874.5603817214.

The spelling of 668912634 in words is "six hundred sixty-eight million, nine hundred twelve thousand, six hundred thirty-four".