681253931 has 2 divisors, whose sum is σ = 681253932. Its totient is φ = 681253930.

The previous prime is 681253927. The next prime is 681253981. The reversal of 681253931 is 139352186.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 681253931 - 2² = 681253927 is a prime.

It is a super-2 number, since 2×681253931² = 928213837005905522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (681253901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340626965 + 340626966.

It is an arithmetic number, because the mean of its divisors is an integer number (340626966).

Almost surely, 2^681253931 is an apocalyptic number.

681253931 is a deficient number, since it is larger than the sum of its proper divisors (1).

681253931 is an equidigital number, since it uses as much as digits as its factorization.

681253931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 681253931 is about 26100.8415764703. The cubic root of 681253931 is about 879.9061241974.

The spelling of 681253931 in words is "six hundred eighty-one million, two hundred fifty-three thousand, nine hundred thirty-one".