638860651 has 16 divisors (see below), whose sum is σ = 751470048. Its totient is φ = 535449600.

The previous prime is 638860643. The next prime is 638860667. The reversal of 638860651 is 156068836.

638860651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 638860651 - 2³ = 638860643 is a prime.

It is a super-2 number, since 2×638860651² = 816285862792287602, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638860598 and 638860607.

It is not an unprimeable number, because it can be changed into a prime (638860151) 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, 140331 + ... + 144811.

It is an arithmetic number, because the mean of its divisors is an integer number (46966878).

Almost surely, 2^638860651 is an apocalyptic number.

638860651 is a deficient number, since it is larger than the sum of its proper divisors (112609397).

638860651 is a wasteful number, since it uses less digits than its factorization.

638860651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5502.

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 638860651 is about 25275.6928886233. The cubic root of 638860651 is about 861.2621862065.

The spelling of 638860651 in words is "six hundred thirty-eight million, eight hundred sixty thousand, six hundred fifty-one".