15661982 has 8 divisors (see below), whose sum is σ = 26849136. Its totient is φ = 6712272.

The previous prime is 15661973. The next prime is 15661991. The reversal of 15661982 is 28916651.

It is an interprime number because it is at equal distance from previous prime (15661973) and next prime (15661991).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 559343 + ... + 559370.

It is an arithmetic number, because the mean of its divisors is an integer number (3356142).

Almost surely, 2^15661982 is an apocalyptic number.

15661982 is a deficient number, since it is larger than the sum of its proper divisors (11187154).

15661982 is a wasteful number, since it uses less digits than its factorization.

15661982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118722.

The product of its digits is 25920, while the sum is 38.

The square root of 15661982 is about 3957.5222046124. The cubic root of 15661982 is about 250.1970819274.

The spelling of 15661982 in words is "fifteen million, six hundred sixty-one thousand, nine hundred eighty-two".