15556205661 has 8 divisors (see below), whose sum is σ = 20752491744. Its totient is φ = 10365361680.

The previous prime is 15556205627. The next prime is 15556205663. The reversal of 15556205661 is 16650265551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15556205661 - 2¹¹ = 15556203613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15556205663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1353850 + ... + 1365291.

It is an arithmetic number, because the mean of its divisors is an integer number (2594061468).

Almost surely, 2^15556205661 is an apocalyptic number.

It is an amenable number.

15556205661 is a deficient number, since it is larger than the sum of its proper divisors (5196286083).

15556205661 is a wasteful number, since it uses less digits than its factorization.

15556205661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2721051.

The product of its (nonzero) digits is 270000, while the sum is 42.

The spelling of 15556205661 in words is "fifteen billion, five hundred fifty-six million, two hundred five thousand, six hundred sixty-one".