51166666665 has 24 divisors (see below), whose sum is σ = 90362268360. Its totient is φ = 26774002944.

The previous prime is 51166666643. The next prime is 51166666669. The reversal of 51166666665 is 56666666115.

It can be written as a sum of positive squares in 4 ways, for example, as 6480089001 + 44686577664 = 80499^2 + 211392^2 .

It is not a de Polignac number, because 51166666665 - 2⁸ = 51166666409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51166666669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10724380 + ... + 10729149.

It is an arithmetic number, because the mean of its divisors is an integer number (3765094515).

Almost surely, 2^51166666665 is an apocalyptic number.

It is an amenable number.

51166666665 is a deficient number, since it is larger than the sum of its proper divisors (39195601695).

51166666665 is a wasteful number, since it uses less digits than its factorization.

51166666665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21453593 (or 21453590 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 54.

The spelling of 51166666665 in words is "fifty-one billion, one hundred sixty-six million, six hundred sixty-six thousand, six hundred sixty-five".