15916644 has 72 divisors (see below), whose sum is σ = 42981120. Its totient is φ = 4954752.

The previous prime is 15916583. The next prime is 15916657. The reversal of 15916644 is 44661951.

15916644 is a `hidden beast` number, since 1 + 5 + 9 + 1 + 6 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 15916599 and 15916608.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38712 + ... + 39120.

It is an arithmetic number, because the mean of its divisors is an integer number (596960).

Almost surely, 2^15916644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15916644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21490560).

15916644 is an abundant number, since it is smaller than the sum of its proper divisors (27064476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15916644 is a wasteful number, since it uses less digits than its factorization.

15916644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489 (or 484 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 15916644 is about 3989.5668937868. The cubic root of 15916644 is about 251.5458562783.

The spelling of 15916644 in words is "fifteen million, nine hundred sixteen thousand, six hundred forty-four".