681877638 has 48 divisors (see below), whose sum is σ = 1645927920. Its totient is φ = 202571712.

The previous prime is 681877631. The next prime is 681877649. The reversal of 681877638 is 836778186.

It is a super-2 number, since 2×681877638² = 929914226408918088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681877631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43456 + ... + 57027.

It is an arithmetic number, because the mean of its divisors is an integer number (34290165).

Almost surely, 2^681877638 is an apocalyptic number.

681877638 is an abundant number, since it is smaller than the sum of its proper divisors (964050282).

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

681877638 is a wasteful number, since it uses less digits than its factorization.

681877638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100533 (or 100530 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The square root of 681877638 is about 26112.7868677397. The cubic root of 681877638 is about 880.1745685016.

The spelling of 681877638 in words is "six hundred eighty-one million, eight hundred seventy-seven thousand, six hundred thirty-eight".