51515155668 has 24 divisors (see below), whose sum is σ = 122997427168. Its totient is φ = 16772376096.

The previous prime is 51515155661. The next prime is 51515155673. The reversal of 51515155668 is 86655151515.

It is a super-2 number, since 2×51515155668² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51515155661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49917271 + ... + 49918302.

Almost surely, 2^51515155668 is an apocalyptic number.

It is an amenable number.

51515155668 is an abundant number, since it is smaller than the sum of its proper divisors (71482271500).

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

51515155668 is a wasteful number, since it uses less digits than its factorization.

51515155668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99835623 (or 99835621 counting only the distinct ones).

The product of its digits is 900000, while the sum is 48.

The spelling of 51515155668 in words is "fifty-one billion, five hundred fifteen million, one hundred fifty-five thousand, six hundred sixty-eight".