51050661665 has 4 divisors (see below), whose sum is σ = 61260794004. Its totient is φ = 40840529328.

The previous prime is 51050661631. The next prime is 51050661667. The reversal of 51050661665 is 56616605015.

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 37598373409 + 13452288256 = 193903^2 + 115984^2 .

It is a cyclic number.

It is not a de Polignac number, because 51050661665 - 2¹⁴ = 51050645281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51050661667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5105066162 + ... + 5105066171.

It is an arithmetic number, because the mean of its divisors is an integer number (15315198501).

Almost surely, 2^51050661665 is an apocalyptic number.

It is an amenable number.

51050661665 is a deficient number, since it is larger than the sum of its proper divisors (10210132339).

51050661665 is a wasteful number, since it uses less digits than its factorization.

51050661665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10210132338.

The product of its (nonzero) digits is 162000, while the sum is 41.

The spelling of 51050661665 in words is "fifty-one billion, fifty million, six hundred sixty-one thousand, six hundred sixty-five".