638865858069 has 16 divisors (see below), whose sum is σ = 946515662400. Its totient is φ = 425889096048.

The previous prime is 638865858011. The next prime is 638865858073. The reversal of 638865858069 is 960858568836.

638865858069 is a `hidden beast` number, since 6 + 38 + 8 + 6 + 5 + 8 + 580 + 6 + 9 = 666.

It is not a de Polignac number, because 638865858069 - 2¹⁹ = 638865333781 is a prime.

It is a super-2 number, since 2×638865858069² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 638865857988 and 638865858006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638865858089) 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, 41799 + ... + 1131140.

It is an arithmetic number, because the mean of its divisors is an integer number (59157228900).

Almost surely, 2^638865858069 is an apocalyptic number.

It is an amenable number.

638865858069 is a deficient number, since it is larger than the sum of its proper divisors (307649804331).

638865858069 is a wasteful number, since it uses less digits than its factorization.

638865858069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193121 (or 1193115 counting only the distinct ones).

The product of its (nonzero) digits is 597196800, while the sum is 72.

The spelling of 638865858069 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, eight hundred fifty-eight thousand, sixty-nine".