638657567465 has 16 divisors (see below), whose sum is σ = 791730094080. Its totient is φ = 494057828160.

The previous prime is 638657567461. The next prime is 638657567479. The reversal of 638657567465 is 564765756836.

It is not a de Polignac number, because 638657567465 - 2² = 638657567461 is a prime.

It is a super-2 number, since 2×638657567465² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 638657567395 and 638657567404.

It is not an unprimeable number, because it can be changed into a prime (638657567461) 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, 1412534 + ... + 1809023.

It is an arithmetic number, because the mean of its divisors is an integer number (49483130880).

Almost surely, 2^638657567465 is an apocalyptic number.

It is an amenable number.

638657567465 is a deficient number, since it is larger than the sum of its proper divisors (153072526615).

638657567465 is a wasteful number, since it uses less digits than its factorization.

638657567465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3222872.

The product of its digits is 762048000, while the sum is 68.

The spelling of 638657567465 in words is "six hundred thirty-eight billion, six hundred fifty-seven million, five hundred sixty-seven thousand, four hundred sixty-five".