51000505551 has 20 divisors (see below), whose sum is σ = 76192030200. Its totient is φ = 33997619376.

The previous prime is 51000505547. The next prime is 51000505553. The reversal of 51000505551 is 15550500015.

51000505551 is a `hidden beast` number, since 5 + 100 + 0 + 5 + 0 + 5 + 551 = 666.

It is not a de Polignac number, because 51000505551 - 2² = 51000505547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51000505553) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1871260 + ... + 1898318.

It is an arithmetic number, because the mean of its divisors is an integer number (3809601510).

Almost surely, 2^51000505551 is an apocalyptic number.

51000505551 is a deficient number, since it is larger than the sum of its proper divisors (25191524649).

51000505551 is a wasteful number, since it uses less digits than its factorization.

51000505551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50340 (or 50331 counting only the distinct ones).

The product of its (nonzero) digits is 3125, while the sum is 27.

The spelling of 51000505551 in words is "fifty-one billion, five hundred five thousand, five hundred fifty-one".