51555121520 has 40 divisors (see below), whose sum is σ = 136989324384. Its totient is φ = 17676041472.

The previous prime is 51555121517. The next prime is 51555121537. The reversal of 51555121520 is 2512155515.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×51555121520² (a number of 22 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 7 ways as a sum of consecutive naturals, for example, 46030799 + ... + 46031918.

Almost surely, 2^51555121520 is an apocalyptic number.

It is an amenable number.

51555121520 is an abundant number, since it is smaller than the sum of its proper divisors (85434202864).

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

51555121520 is a wasteful number, since it uses less digits than its factorization.

51555121520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92062737 (or 92062731 counting only the distinct ones).

The product of its (nonzero) digits is 12500, while the sum is 32.

The spelling of 51555121520 in words is "fifty-one billion, five hundred fifty-five million, one hundred twenty-one thousand, five hundred twenty".