638580885551 has 16 divisors (see below), whose sum is σ = 776110962240. Its totient is φ = 512908070400.

The previous prime is 638580885479. The next prime is 638580885583. The reversal of 638580885551 is 155588085836.

It is a cyclic number.

It is not a de Polignac number, because 638580885551 - 2³⁰ = 637507143727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638580885251) 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, 11689400 + ... + 11743901.

It is an arithmetic number, because the mean of its divisors is an integer number (48506935140).

Almost surely, 2^638580885551 is an apocalyptic number.

638580885551 is a deficient number, since it is larger than the sum of its proper divisors (137530076689).

638580885551 is a wasteful number, since it uses less digits than its factorization.

638580885551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23433554.

The product of its (nonzero) digits is 46080000, while the sum is 62.

The spelling of 638580885551 in words is "six hundred thirty-eight billion, five hundred eighty million, eight hundred eighty-five thousand, five hundred fifty-one".