664838653631 has 2 divisors, whose sum is σ = 664838653632. Its totient is φ = 664838653630.

The previous prime is 664838653541. The next prime is 664838653639. The reversal of 664838653631 is 136356838466.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664838653631 is a prime.

It is a super-2 number, since 2×664838653631² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664838653639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332419326815 + 332419326816.

It is an arithmetic number, because the mean of its divisors is an integer number (332419326816).

Almost surely, 2^664838653631 is an apocalyptic number.

664838653631 is a deficient number, since it is larger than the sum of its proper divisors (1).

664838653631 is an equidigital number, since it uses as much as digits as its factorization.

664838653631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 44789760, while the sum is 59.

The spelling of 664838653631 in words is "six hundred sixty-four billion, eight hundred thirty-eight million, six hundred fifty-three thousand, six hundred thirty-one".