681025640 has 16 divisors (see below), whose sum is σ = 1532307780. Its totient is φ = 272410240.

The previous prime is 681025637. The next prime is 681025643. The reversal of 681025640 is 46520186.

It is an interprime number because it is at equal distance from previous prime (681025637) and next prime (681025643).

It can be written as a sum of positive squares in 2 ways, for example, as 639988804 + 41036836 = 25298^2 + 6406^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681025597 and 681025606.

It is not an unprimeable number, because it can be changed into a prime (681025643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8512781 + ... + 8512860.

Almost surely, 2^681025640 is an apocalyptic number.

It is an amenable number.

681025640 is an abundant number, since it is smaller than the sum of its proper divisors (851282140).

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

681025640 is a wasteful number, since it uses less digits than its factorization.

681025640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17025652 (or 17025648 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 681025640 is about 26096.4679602432. The cubic root of 681025640 is about 879.8078264937.

The spelling of 681025640 in words is "six hundred eighty-one million, twenty-five thousand, six hundred forty".