638181466497 has 28 divisors (see below), whose sum is σ = 965776986000. Its totient is φ = 421478050968.

The previous prime is 638181466477. The next prime is 638181466501. The reversal of 638181466497 is 794664181836.

It is a happy number.

638181466497 is a `hidden beast` number, since 6 + 3 + 8 + 1 + 81 + 4 + 66 + 497 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-638181466497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638181466477) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 4012747 + ... + 4168752.

Almost surely, 2^638181466497 is an apocalyptic number.

It is an amenable number.

638181466497 is a deficient number, since it is larger than the sum of its proper divisors (327595519503).

638181466497 is an equidigital number, since it uses as much as digits as its factorization.

638181466497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8181624 (or 8181609 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 638181466497 in words is "six hundred thirty-eight billion, one hundred eighty-one million, four hundred sixty-six thousand, four hundred ninety-seven".