51617065665 has 16 divisors (see below), whose sum is σ = 90095242176. Its totient is φ = 25026456000.

The previous prime is 51617065637. The next prime is 51617065691. The reversal of 51617065665 is 56656071615.

It is not a de Polignac number, because 51617065665 - 2⁶ = 51617065601 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, 156415186 + ... + 156415515.

It is an arithmetic number, because the mean of its divisors is an integer number (5630952636).

Almost surely, 2^51617065665 is an apocalyptic number.

51617065665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51617065665 is a deficient number, since it is larger than the sum of its proper divisors (38478176511).

51617065665 is a wasteful number, since it uses less digits than its factorization.

51617065665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312830720.

The product of its (nonzero) digits is 1134000, while the sum is 48.

The spelling of 51617065665 in words is "fifty-one billion, six hundred seventeen million, sixty-five thousand, six hundred sixty-five".