638865678606 has 32 divisors (see below), whose sum is σ = 1298739949728. Its totient is φ = 209454128640.

The previous prime is 638865678599. The next prime is 638865678617. The reversal of 638865678606 is 606876568836.

638865678606 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×638865678606² (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 15 ways as a sum of consecutive naturals, for example, 15026130 + ... + 15068586.

It is an arithmetic number, because the mean of its divisors is an integer number (40585623429).

Almost surely, 2^638865678606 is an apocalyptic number.

638865678606 is an abundant number, since it is smaller than the sum of its proper divisors (659874271122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638865678606 is a wasteful number, since it uses less digits than its factorization.

638865678606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83636.

The product of its (nonzero) digits is 418037760, while the sum is 69.

The spelling of 638865678606 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, six hundred seventy-eight thousand, six hundred six".