681908740 has 12 divisors (see below), whose sum is σ = 1432008396. Its totient is φ = 272763488.

The previous prime is 681908713. The next prime is 681908741. The reversal of 681908740 is 47809186.

It can be written as a sum of positive squares in 2 ways, for example, as 433972224 + 247936516 = 20832^2 + 15746^2 .

It is not an unprimeable number, because it can be changed into a prime (681908741) 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, 17047699 + ... + 17047738.

It is an arithmetic number, because the mean of its divisors is an integer number (119334033).

Almost surely, 2^681908740 is an apocalyptic number.

It is an amenable number.

681908740 is an abundant number, since it is smaller than the sum of its proper divisors (750099656).

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

681908740 is a wasteful number, since it uses less digits than its factorization.

681908740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34095446 (or 34095444 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 681908740 is about 26113.3823929417. The cubic root of 681908740 is about 880.1879505571.

The spelling of 681908740 in words is "six hundred eighty-one million, nine hundred eight thousand, seven hundred forty".