51142902161 has 4 divisors (see below), whose sum is σ = 55076971572. Its totient is φ = 47208832752.

The previous prime is 51142902157. The next prime is 51142902191. The reversal of 51142902161 is 16120924115.

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 19865211136 + 31277691025 = 140944^2 + 176855^2 .

It is a cyclic number.

It is not a de Polignac number, because 51142902161 - 2² = 51142902157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51142902191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1967034686 + ... + 1967034711.

It is an arithmetic number, because the mean of its divisors is an integer number (13769242893).

Almost surely, 2^51142902161 is an apocalyptic number.

It is an amenable number.

51142902161 is a deficient number, since it is larger than the sum of its proper divisors (3934069411).

51142902161 is a wasteful number, since it uses less digits than its factorization.

51142902161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3934069410.

The product of its (nonzero) digits is 4320, while the sum is 32.

The spelling of 51142902161 in words is "fifty-one billion, one hundred forty-two million, nine hundred two thousand, one hundred sixty-one".