15951816 has 80 divisors (see below), whose sum is σ = 45302400. Its totient is φ = 5243616.

The previous prime is 15951787. The next prime is 15951821. The reversal of 15951816 is 61815951.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

Its product of digits (10800) is a multiple of the sum of its prime factors (360).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 66625 + ... + 66863.

It is an arithmetic number, because the mean of its divisors is an integer number (566280).

Almost surely, 2^15951816 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 15951816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22651200).

15951816 is an abundant number, since it is smaller than the sum of its proper divisors (29350584).

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

15951816 is a wasteful number, since it uses less digits than its factorization.

15951816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360 (or 347 counting only the distinct ones).

The product of its digits is 10800, while the sum is 36.

The square root of 15951816 is about 3993.9724585931. The cubic root of 15951816 is about 251.7310054841.

The spelling of 15951816 in words is "fifteen million, nine hundred fifty-one thousand, eight hundred sixteen".