815616 has 80 divisors (see below), whose sum is σ = 2455200. Its totient is φ = 267264.

The previous prime is 815599. The next prime is 815621. The reversal of 815616 is 616518.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 815616.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13795 + ... + 13853.

It is an arithmetic number, because the mean of its divisors is an integer number (30690).

2⁸¹⁵⁶¹⁶ 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 815616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1227600).

815616 is an abundant number, since it is smaller than the sum of its proper divisors (1639584).

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

815616 is an equidigital number, since it uses as much as digits as its factorization.

815616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 64 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 815616 is about 903.1146106669. The cubic root of 815616 is about 93.4319139810.

It can be divided in two parts, 815 and 616, that added together give a triangular number (1431 = T₅₃).

The spelling of 815616 in words is "eight hundred fifteen thousand, six hundred sixteen".