51160661665 has 4 divisors (see below), whose sum is σ = 61392794004. Its totient is φ = 40928529328.

The previous prime is 51160661627. The next prime is 51160661677. The reversal of 51160661665 is 56616606115.

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 10503585169 + 40657076496 = 102487^2 + 201636^2 .

It is a cyclic number.

It is not a de Polignac number, because 51160661665 - 2⁷ = 51160661537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5116066162 + ... + 5116066171.

It is an arithmetic number, because the mean of its divisors is an integer number (15348198501).

Almost surely, 2^51160661665 is an apocalyptic number.

It is an amenable number.

51160661665 is a deficient number, since it is larger than the sum of its proper divisors (10232132339).

51160661665 is a wasteful number, since it uses less digits than its factorization.

51160661665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10232132338.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 51160661665 in words is "fifty-one billion, one hundred sixty million, six hundred sixty-one thousand, six hundred sixty-five".