51605166217 has 24 divisors (see below), whose sum is σ = 60023134080. Its totient is φ = 44241859200.

The previous prime is 51605166199. The next prime is 51605166227. The reversal of 51605166217 is 71266150615.

It is not a de Polignac number, because 51605166217 - 2⁷ = 51605166089 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51605166217.

It is not an unprimeable number, because it can be changed into a prime (51605166227) 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, 67009 + ... + 328177.

It is an arithmetic number, because the mean of its divisors is an integer number (2500963920).

Almost surely, 2^51605166217 is an apocalyptic number.

It is an amenable number.

51605166217 is a deficient number, since it is larger than the sum of its proper divisors (8417967863).

51605166217 is a wasteful number, since it uses less digits than its factorization.

51605166217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261285 (or 261274 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 40.

The spelling of 51605166217 in words is "fifty-one billion, six hundred five million, one hundred sixty-six thousand, two hundred seventeen".