51638687808 has 28 divisors (see below), whose sum is σ = 136627362000. Its totient is φ = 17212895872.

The previous prime is 51638687801. The next prime is 51638687827. The reversal of 51638687808 is 80878683615.

It is a super-4 number, since 4×51638687808⁴ (a number of 44 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (51638687801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134475558 + ... + 134475941.

Almost surely, 2^51638687808 is an apocalyptic number.

It is an amenable number.

51638687808 is an abundant number, since it is smaller than the sum of its proper divisors (84988674192).

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

51638687808 is a wasteful number, since it uses less digits than its factorization.

51638687808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268951514 (or 268951504 counting only the distinct ones).

The product of its (nonzero) digits is 15482880, while the sum is 60.

The spelling of 51638687808 in words is "fifty-one billion, six hundred thirty-eight million, six hundred eighty-seven thousand, eight hundred eight".