15661661155 has 16 divisors (see below), whose sum is σ = 21679591680. Its totient is φ = 10639053792.

The previous prime is 15661661153. The next prime is 15661661177. The reversal of 15661661155 is 55116616651.

It is a cyclic number.

It is not a de Polignac number, because 15661661155 - 2¹ = 15661661153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15661661153) 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, 2087265 + ... + 2094754.

It is an arithmetic number, because the mean of its divisors is an integer number (1354974480).

Almost surely, 2^15661661155 is an apocalyptic number.

15661661155 is a deficient number, since it is larger than the sum of its proper divisors (6017930525).

15661661155 is a wasteful number, since it uses less digits than its factorization.

15661661155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4182138.

The product of its digits is 162000, while the sum is 43.

The spelling of 15661661155 in words is "fifteen billion, six hundred sixty-one million, six hundred sixty-one thousand, one hundred fifty-five".