15561161 has 16 divisors (see below), whose sum is σ = 19724928. Its totient is φ = 11923200.

The previous prime is 15561157. The next prime is 15561173. The reversal of 15561161 is 16116551.

It is a cyclic number.

It is not a de Polignac number, because 15561161 - 2² = 15561157 is a prime.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 15561161.

It is not an unprimeable number, because it can be changed into a prime (15561131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3041 + ... + 6353.

It is an arithmetic number, because the mean of its divisors is an integer number (1232808).

Almost surely, 2^15561161 is an apocalyptic number.

15561161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15561161 is a deficient number, since it is larger than the sum of its proper divisors (4163767).

15561161 is a wasteful number, since it uses less digits than its factorization.

15561161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3392.

The product of its digits is 900, while the sum is 26.

The square root of 15561161 is about 3944.7637445099. The cubic root of 15561161 is about 249.6590605860.

It can be divided in two parts, 155 and 61161, that added together give a palindrome (61316).

The spelling of 15561161 in words is "fifteen million, five hundred sixty-one thousand, one hundred sixty-one".