51666665515 has 16 divisors (see below), whose sum is σ = 65591136000. Its totient is φ = 38961106272.

The previous prime is 51666665473. The next prime is 51666665521. The reversal of 51666665515 is 51556666615.

It is a cyclic number.

It is not a de Polignac number, because 51666665515 - 2¹¹ = 51666663467 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1347577 + ... + 1385386.

It is an arithmetic number, because the mean of its divisors is an integer number (4099446000).

Almost surely, 2^51666665515 is an apocalyptic number.

51666665515 is a deficient number, since it is larger than the sum of its proper divisors (13924470485).

51666665515 is a wasteful number, since it uses less digits than its factorization.

51666665515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2733186.

The product of its digits is 4860000, while the sum is 52.

The spelling of 51666665515 in words is "fifty-one billion, six hundred sixty-six million, six hundred sixty-five thousand, five hundred fifteen".