638860330831 has 2 divisors, whose sum is σ = 638860330832. Its totient is φ = 638860330830.

The previous prime is 638860330819. The next prime is 638860330883. The reversal of 638860330831 is 138033068836.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638860330831 - 2²¹ = 638858233679 is a prime.

It is a super-2 number, since 2×638860330831² (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 (638860330331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319430165415 + 319430165416.

It is an arithmetic number, because the mean of its divisors is an integer number (319430165416).

Almost surely, 2^638860330831 is an apocalyptic number.

638860330831 is a deficient number, since it is larger than the sum of its proper divisors (1).

638860330831 is an equidigital number, since it uses as much as digits as its factorization.

638860330831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1492992, while the sum is 49.

The spelling of 638860330831 in words is "six hundred thirty-eight billion, eight hundred sixty million, three hundred thirty thousand, eight hundred thirty-one".