681664902 has 16 divisors (see below), whose sum is σ = 1364090112. Its totient is φ = 227094920.

The previous prime is 681664897. The next prime is 681664909. The reversal of 681664902 is 209466186.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681664909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19674 + ... + 41837.

It is an arithmetic number, because the mean of its divisors is an integer number (85255632).

Almost surely, 2^681664902 is an apocalyptic number.

681664902 is an abundant number, since it is smaller than the sum of its proper divisors (682425210).

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

681664902 is a wasteful number, since it uses less digits than its factorization.

681664902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63363.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 681664902 is about 26108.7131433167. The cubic root of 681664902 is about 880.0830250523.

The spelling of 681664902 in words is "six hundred eighty-one million, six hundred sixty-four thousand, nine hundred two".