64638631 has 2 divisors, whose sum is σ = 64638632. Its totient is φ = 64638630.

The previous prime is 64638619. The next prime is 64638647. The reversal of 64638631 is 13683646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64638631 - 2¹³ = 64630439 is a prime.

It is a super-2 number, since 2×64638631² = 8356305235108322, 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 (64638601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32319315 + 32319316.

It is an arithmetic number, because the mean of its divisors is an integer number (32319316).

Almost surely, 2^64638631 is an apocalyptic number.

64638631 is a deficient number, since it is larger than the sum of its proper divisors (1).

64638631 is an equidigital number, since it uses as much as digits as its factorization.

64638631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 37.

The square root of 64638631 is about 8039.8153585763. The cubic root of 64638631 is about 401.3260801703.

The spelling of 64638631 in words is "sixty-four million, six hundred thirty-eight thousand, six hundred thirty-one".