51561605279 has 4 divisors (see below), whose sum is σ = 51563308080. Its totient is φ = 51559902480.

The previous prime is 51561605269. The next prime is 51561605287. The reversal of 51561605279 is 97250616515.

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

It is a cyclic number.

It is not a de Polignac number, because 51561605279 - 2⁸ = 51561605023 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 (51561605239) 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, 805142 + ... + 866819.

It is an arithmetic number, because the mean of its divisors is an integer number (12890827020).

Almost surely, 2^51561605279 is an apocalyptic number.

51561605279 is a deficient number, since it is larger than the sum of its proper divisors (1702801).

51561605279 is a wasteful number, since it uses less digits than its factorization.

51561605279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702800.

The product of its (nonzero) digits is 567000, while the sum is 47.

The spelling of 51561605279 in words is "fifty-one billion, five hundred sixty-one million, six hundred five thousand, two hundred seventy-nine".