638654052731 has 2 divisors, whose sum is σ = 638654052732. Its totient is φ = 638654052730.

The previous prime is 638654052721. The next prime is 638654052761. The reversal of 638654052731 is 137250456836.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638654052731 is a prime.

It is a super-2 number, since 2×638654052731² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 638654052731.

It is not a weakly prime, because it can be changed into another prime (638654052721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319327026365 + 319327026366.

It is an arithmetic number, because the mean of its divisors is an integer number (319327026366).

Almost surely, 2^638654052731 is an apocalyptic number.

638654052731 is a deficient number, since it is larger than the sum of its proper divisors (1).

638654052731 is an equidigital number, since it uses as much as digits as its factorization.

638654052731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3628800, while the sum is 50.

The spelling of 638654052731 in words is "six hundred thirty-eight billion, six hundred fifty-four million, fifty-two thousand, seven hundred thirty-one".