690844631 has 2 divisors, whose sum is σ = 690844632. Its totient is φ = 690844630.

The previous prime is 690844603. The next prime is 690844639. The reversal of 690844631 is 136448096.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690844631 is a prime.

It is a super-2 number, since 2×690844631² = 954532608363052322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690844639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345422315 + 345422316.

It is an arithmetic number, because the mean of its divisors is an integer number (345422316).

Almost surely, 2^690844631 is an apocalyptic number.

690844631 is a deficient number, since it is larger than the sum of its proper divisors (1).

690844631 is an equidigital number, since it uses as much as digits as its factorization.

690844631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 690844631 is about 26283.9234323949. The cubic root of 690844631 is about 884.0160070093.

The spelling of 690844631 in words is "six hundred ninety million, eight hundred forty-four thousand, six hundred thirty-one".