1616716521561 has 16 divisors (see below), whose sum is σ = 2204067366144. Its totient is φ = 1053642117504.

The previous prime is 1616716521527. The next prime is 1616716521587. The reversal of 1616716521561 is 1651256176161.

It is not a de Polignac number, because 1616716521561 - 2²⁵ = 1616682967129 is a prime.

It is a super-2 number, since 2×1616716521561² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1616716521561.

It is not an unprimeable number, because it can be changed into a prime (1616716521061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6600756 + ... + 6841301.

It is an arithmetic number, because the mean of its divisors is an integer number (137754210384).

Almost surely, 2^{1616716521561} is an apocalyptic number.

It is an amenable number.

1616716521561 is a deficient number, since it is larger than the sum of its proper divisors (587350844583).

1616716521561 is a wasteful number, since it uses less digits than its factorization.

1616716521561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13442960.

The product of its digits is 453600, while the sum is 48.

The spelling of 1616716521561 in words is "one trillion, six hundred sixteen billion, seven hundred sixteen million, five hundred twenty-one thousand, five hundred sixty-one".