51715700650021 has 4 divisors (see below), whose sum is σ = 52248852203212. Its totient is φ = 51182549096832.

The previous prime is 51715700650007. The next prime is 51715700650049. The reversal of 51715700650021 is 12005600751715.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14135870452900 + 37579830197121 = 3759770^2 + 6130239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51715700650021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51715700650921) 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, 266575776450 + ... + 266575776643.

It is an arithmetic number, because the mean of its divisors is an integer number (13062213050803).

Almost surely, 2^{51715700650021} is an apocalyptic number.

It is an amenable number.

51715700650021 is a deficient number, since it is larger than the sum of its proper divisors (533151553191).

51715700650021 is an equidigital number, since it uses as much as digits as its factorization.

51715700650021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533151553190.

The product of its (nonzero) digits is 73500, while the sum is 40.

The spelling of 51715700650021 in words is "fifty-one trillion, seven hundred fifteen billion, seven hundred million, six hundred fifty thousand, twenty-one".