681279731 has 6 divisors (see below), whose sum is σ = 748844796. Its totient is φ = 619345100.

The previous prime is 681279721. The next prime is 681279737. The reversal of 681279731 is 137972186.

It is not a de Polignac number, because 681279731 - 2²² = 677085427 is a prime.

It is a super-2 number, since 2×681279731² = 928284143742864722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681279737) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2815085 + ... + 2815326.

It is an arithmetic number, because the mean of its divisors is an integer number (124807466).

Almost surely, 2^681279731 is an apocalyptic number.

681279731 is a deficient number, since it is larger than the sum of its proper divisors (67565065).

681279731 is a wasteful number, since it uses less digits than its factorization.

681279731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5630433 (or 5630422 counting only the distinct ones).

The product of its digits is 127008, while the sum is 44.

The square root of 681279731 is about 26101.3358087283. The cubic root of 681279731 is about 879.9172317988.

The spelling of 681279731 in words is "six hundred eighty-one million, two hundred seventy-nine thousand, seven hundred thirty-one".