51516655661515 has 16 divisors (see below), whose sum is σ = 67440282430176. Its totient is φ = 37466493753600.

The previous prime is 51516655661503. The next prime is 51516655661561.

51516655661515 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 51516655661515 - 2¹⁷ = 51516655530443 is a prime.

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 51516655661515.

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, 11331949 + ... + 15213361.

It is an arithmetic number, because the mean of its divisors is an integer number (4215017651886).

Almost surely, 2^{51516655661515} is an apocalyptic number.

51516655661515 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51516655661515 is a deficient number, since it is larger than the sum of its proper divisors (15923626768661).

51516655661515 is a wasteful number, since it uses less digits than its factorization.

51516655661515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4122750.

The product of its digits is 20250000, while the sum is 58.

The spelling of 51516655661515 in words is "fifty-one trillion, five hundred sixteen billion, six hundred fifty-five million, six hundred sixty-one thousand, five hundred fifteen".