681397791731 has 8 divisors (see below), whose sum is σ = 721497143664. Its totient is φ = 641300343040.

The previous prime is 681397791719. The next prime is 681397791797. The reversal of 681397791731 is 137197793186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681397791731 - 2²⁶ = 681330682867 is a prime.

It is a super-2 number, since 2×681397791731² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681397791131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 297191 + ... + 1204623.

It is an arithmetic number, because the mean of its divisors is an integer number (90187142958).

Almost surely, 2^681397791731 is an apocalyptic number.

681397791731 is a deficient number, since it is larger than the sum of its proper divisors (40099351933).

681397791731 is a wasteful number, since it uses less digits than its factorization.

681397791731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951621.

The product of its digits is 12002256, while the sum is 62.

The spelling of 681397791731 in words is "six hundred eighty-one billion, three hundred ninety-seven million, seven hundred ninety-one thousand, seven hundred thirty-one".