51005651251 has 4 divisors (see below), whose sum is σ = 51006232872. Its totient is φ = 51005069632.

The previous prime is 51005651219. The next prime is 51005651309. The reversal of 51005651251 is 15215650015.

51005651251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 51005651251 - 2⁵ = 51005651219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51005651201) 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, 129406 + ... + 344611.

It is an arithmetic number, because the mean of its divisors is an integer number (12751558218).

Almost surely, 2^51005651251 is an apocalyptic number.

51005651251 is a deficient number, since it is larger than the sum of its proper divisors (581621).

51005651251 is a wasteful number, since it uses less digits than its factorization.

51005651251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581620.

The product of its (nonzero) digits is 7500, while the sum is 31.

The spelling of 51005651251 in words is "fifty-one billion, five million, six hundred fifty-one thousand, two hundred fifty-one".