646277431 has 2 divisors, whose sum is σ = 646277432. Its totient is φ = 646277430.

The previous prime is 646277407. The next prime is 646277447. The reversal of 646277431 is 134772646.

646277431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646277431 is a prime.

It is a super-2 number, since 2×646277431² = 835349035639919522, which contains 22 as substring.

It is equal to p_33609865 and since 646277431 and 33609865 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646277461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323138715 + 323138716.

It is an arithmetic number, because the mean of its divisors is an integer number (323138716).

Almost surely, 2^646277431 is an apocalyptic number.

646277431 is a deficient number, since it is larger than the sum of its proper divisors (1).

646277431 is an equidigital number, since it uses as much as digits as its factorization.

646277431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 40.

The square root of 646277431 is about 25421.9871567901. The cubic root of 646277431 is about 864.5822795150.

The spelling of 646277431 in words is "six hundred forty-six million, two hundred seventy-seven thousand, four hundred thirty-one".