638612160781 has 8 divisors (see below), whose sum is σ = 737068633344. Its totient is φ = 541962229200.

The previous prime is 638612160727. The next prime is 638612160799. The reversal of 638612160781 is 187061216836.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638612160781 - 2³⁵ = 604252422413 is a prime.

It is a super-2 number, since 2×638612160781² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638612166781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 451634485 + ... + 451635898.

It is an arithmetic number, because the mean of its divisors is an integer number (92133579168).

Almost surely, 2^638612160781 is an apocalyptic number.

It is an amenable number.

638612160781 is a deficient number, since it is larger than the sum of its proper divisors (98456472563).

638612160781 is a wasteful number, since it uses less digits than its factorization.

638612160781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903270491.

The product of its (nonzero) digits is 580608, while the sum is 49.

The spelling of 638612160781 in words is "six hundred thirty-eight billion, six hundred twelve million, one hundred sixty thousand, seven hundred eighty-one".