681369680 has 20 divisors (see below), whose sum is σ = 1584184692. Its totient is φ = 272547840.

The previous prime is 681369653. The next prime is 681369719. The reversal of 681369680 is 86963186.

It can be written as a sum of positive squares in 2 ways, for example, as 150896656 + 530473024 = 12284^2 + 23032^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 4258481 + ... + 4258640.

Almost surely, 2^681369680 is an apocalyptic number.

It is an amenable number.

681369680 is an abundant number, since it is smaller than the sum of its proper divisors (902815012).

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

681369680 is a wasteful number, since it uses less digits than its factorization.

681369680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8517134 (or 8517128 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 47.

The square root of 681369680 is about 26103.0588245899. The cubic root of 681369680 is about 879.9559550958.

The spelling of 681369680 in words is "six hundred eighty-one million, three hundred sixty-nine thousand, six hundred eighty".