51561537379 has 24 divisors (see below), whose sum is σ = 58884544512. Its totient is φ = 44691419520.

The previous prime is 51561537373. The next prime is 51561537409. The reversal of 51561537379 is 97373516515.

It is a happy number.

It is not a de Polignac number, because 51561537379 - 2²⁹ = 51024666467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51561537373) 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 23 ways as a sum of consecutive naturals, for example, 47434174 + ... + 47435260.

It is an arithmetic number, because the mean of its divisors is an integer number (2453522688).

Almost surely, 2^51561537379 is an apocalyptic number.

51561537379 is a deficient number, since it is larger than the sum of its proper divisors (7323007133).

51561537379 is a wasteful number, since it uses less digits than its factorization.

51561537379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1987 (or 1554 counting only the distinct ones).

The product of its digits is 2976750, while the sum is 52.

The spelling of 51561537379 in words is "fifty-one billion, five hundred sixty-one million, five hundred thirty-seven thousand, three hundred seventy-nine".