815880 has 64 divisors (see below), whose sum is σ = 2640960. Its totient is φ = 200448.

The previous prime is 815869. The next prime is 815891. The reversal of 815880 is 88518.

815880 = T₂₆ + T₂₇ + ... + T₁₆₉.

It is an interprime number because it is at equal distance from previous prime (815869) and next prime (815891).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1299 + ... + 1821.

It is an arithmetic number, because the mean of its divisors is an integer number (41265).

2⁸¹⁵⁸⁸⁰ 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 815880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1320480).

815880 is an abundant number, since it is smaller than the sum of its proper divisors (1825080).

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

815880 is a wasteful number, since it uses less digits than its factorization.

815880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 30.

The square root of 815880 is about 903.2607596923. The cubic root of 815880 is about 93.4419936281.

The spelling of 815880 in words is "eight hundred fifteen thousand, eight hundred eighty".