5611221561 has 32 divisors (see below), whose sum is σ = 8264664576. Its totient is φ = 3358080000.

The previous prime is 5611221541. The next prime is 5611221587. The reversal of 5611221561 is 1651221165.

It is not a de Polignac number, because 5611221561 - 2¹¹ = 5611219513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (5611221521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1166361 + ... + 1171161.

It is an arithmetic number, because the mean of its divisors is an integer number (258270768).

Almost surely, 2^5611221561 is an apocalyptic number.

It is an amenable number.

5611221561 is a deficient number, since it is larger than the sum of its proper divisors (2653443015).

5611221561 is a wasteful number, since it uses less digits than its factorization.

5611221561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253.

The product of its digits is 3600, while the sum is 30.

The square root of 5611221561 is about 74908.0874205182. The cubic root of 5611221561 is about 1776.9933631380.

The spelling of 5611221561 in words is "five billion, six hundred eleven million, two hundred twenty-one thousand, five hundred sixty-one".