638454456831 has 16 divisors (see below), whose sum is σ = 898478810240. Its totient is φ = 402153323040.

The previous prime is 638454456811. The next prime is 638454456863. The reversal of 638454456831 is 138654454836.

It is not a de Polignac number, because 638454456831 - 2¹⁸ = 638454194687 is a prime.

It is a super-2 number, since 2×638454456831² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638454456811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14993425 + ... + 15035946.

It is an arithmetic number, because the mean of its divisors is an integer number (56154925640).

Almost surely, 2^638454456831 is an apocalyptic number.

638454456831 is a deficient number, since it is larger than the sum of its proper divisors (260024353409).

638454456831 is a wasteful number, since it uses less digits than its factorization.

638454456831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30029766.

The product of its digits is 33177600, while the sum is 57.

The spelling of 638454456831 in words is "six hundred thirty-eight billion, four hundred fifty-four million, four hundred fifty-six thousand, eight hundred thirty-one".