51551679565 has 4 divisors (see below), whose sum is σ = 61862015484. Its totient is φ = 41241343648.

The previous prime is 51551679511. The next prime is 51551679577. The reversal of 51551679565 is 56597615515.

It is a happy number.

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 30949957476 + 20601722089 = 175926^2 + 143533^2 .

It is a cyclic number.

It is not a de Polignac number, because 51551679565 - 2²³ = 51543290957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5155167952 + ... + 5155167961.

It is an arithmetic number, because the mean of its divisors is an integer number (15465503871).

Almost surely, 2^51551679565 is an apocalyptic number.

It is an amenable number.

51551679565 is a deficient number, since it is larger than the sum of its proper divisors (10310335919).

51551679565 is a wasteful number, since it uses less digits than its factorization.

51551679565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10310335918.

The product of its digits is 7087500, while the sum is 55.

The spelling of 51551679565 in words is "fifty-one billion, five hundred fifty-one million, six hundred seventy-nine thousand, five hundred sixty-five".