15661955 has 8 divisors (see below), whose sum is σ = 18820032. Its totient is φ = 12512448.

The previous prime is 15661949. The next prime is 15661957. The reversal of 15661955 is 55916651.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15661955 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661957) 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, 3014 + ... + 6356.

It is an arithmetic number, because the mean of its divisors is an integer number (2352504).

Almost surely, 2^15661955 is an apocalyptic number.

15661955 is a deficient number, since it is larger than the sum of its proper divisors (3158077).

15661955 is an equidigital number, since it uses as much as digits as its factorization.

15661955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4285.

The product of its digits is 40500, while the sum is 38.

The square root of 15661955 is about 3957.5187933856. The cubic root of 15661955 is about 250.1969381541.

The spelling of 15661955 in words is "fifteen million, six hundred sixty-one thousand, nine hundred fifty-five".