55121221617 has 64 divisors (see below), whose sum is σ = 97260134400. Its totient is φ = 26883348480.

The previous prime is 55121221567. The next prime is 55121221621. The reversal of 55121221617 is 71612212155.

It is not a de Polignac number, because 55121221617 - 2⁸ = 55121221361 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (55121221637) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1588984 + ... + 1623302.

It is an arithmetic number, because the mean of its divisors is an integer number (1519689600).

Almost surely, 2^55121221617 is an apocalyptic number.

It is an amenable number.

55121221617 is a deficient number, since it is larger than the sum of its proper divisors (42138912783).

55121221617 is a wasteful number, since it uses less digits than its factorization.

55121221617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34766.

The product of its digits is 8400, while the sum is 33.

The spelling of 55121221617 in words is "fifty-five billion, one hundred twenty-one million, two hundred twenty-one thousand, six hundred seventeen".