668781089424 has 120 divisors (see below), whose sum is σ = 2139583897152. Its totient is φ = 191031540480.

The previous prime is 668781089401. The next prime is 668781089429. The reversal of 668781089424 is 424980187866.

668781089424 is a `hidden beast` number, since 6 + 68 + 78 + 1 + 0 + 89 + 424 = 666.

668781089424 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 (63).

It is not an unprimeable number, because it can be changed into a prime (668781089429) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3962439 + ... + 4127769.

Almost surely, 2^668781089424 is an apocalyptic number.

It is an amenable number.

668781089424 is an abundant number, since it is smaller than the sum of its proper divisors (1470802807728).

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

668781089424 is a wasteful number, since it uses less digits than its factorization.

668781089424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169365 (or 169356 counting only the distinct ones).

The product of its (nonzero) digits is 37158912, while the sum is 63.

The spelling of 668781089424 in words is "six hundred sixty-eight billion, seven hundred eighty-one million, eighty-nine thousand, four hundred twenty-four".