638820158044 has 24 divisors (see below), whose sum is σ = 1118696342400. Its totient is φ = 319192713840.

The previous prime is 638820158029. The next prime is 638820158099. The reversal of 638820158044 is 440851028836.

It is a super-2 number, since 2×638820158044² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48173487 + ... + 48186745.

It is an arithmetic number, because the mean of its divisors is an integer number (46612347600).

Almost surely, 2^638820158044 is an apocalyptic number.

It is an amenable number.

638820158044 is a deficient number, since it is larger than the sum of its proper divisors (479876184356).

638820158044 is a wasteful number, since it uses less digits than its factorization.

638820158044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20553 (or 20551 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 49.

The spelling of 638820158044 in words is "six hundred thirty-eight billion, eight hundred twenty million, one hundred fifty-eight thousand, forty-four".