681912518 has 24 divisors (see below), whose sum is σ = 1228256064. Its totient is φ = 282819600.

The previous prime is 681912499. The next prime is 681912521. The reversal of 681912518 is 815219186.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109193 + ... + 115268.

It is an arithmetic number, because the mean of its divisors is an integer number (51177336).

Almost surely, 2^681912518 is an apocalyptic number.

681912518 is a deficient number, since it is larger than the sum of its proper divisors (546343546).

681912518 is a wasteful number, since it uses less digits than its factorization.

681912518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224508 (or 224501 counting only the distinct ones).

The product of its digits is 34560, while the sum is 41.

The square root of 681912518 is about 26113.4547312300. The cubic root of 681912518 is about 880.1895760649.

The spelling of 681912518 in words is "six hundred eighty-one million, nine hundred twelve thousand, five hundred eighteen".