681835631 has 2 divisors, whose sum is σ = 681835632. Its totient is φ = 681835630.

The previous prime is 681835603. The next prime is 681835633. The reversal of 681835631 is 136538186.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 681835631 - 2¹⁴ = 681819247 is a prime.

It is a super-2 number, since 2×681835631² = 929799655402336322, which contains 22 as substring.

Together with 681835633, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681835633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340917815 + 340917816.

It is an arithmetic number, because the mean of its divisors is an integer number (340917816).

Almost surely, 2^681835631 is an apocalyptic number.

681835631 is a deficient number, since it is larger than the sum of its proper divisors (1).

681835631 is an equidigital number, since it uses as much as digits as its factorization.

681835631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 681835631 is about 26111.9825176106. The cubic root of 681835631 is about 880.1564937766.

The spelling of 681835631 in words is "six hundred eighty-one million, eight hundred thirty-five thousand, six hundred thirty-one".