815920 has 80 divisors (see below), whose sum is σ = 2285568. Its totient is φ = 264960.

The previous prime is 815897. The next prime is 815923. The reversal of 815920 is 29518.

It is a tau number, because it is divible by the number of its divisors (80).

It is a nialpdrome in base 16.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (815923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17337 + ... + 17383.

2⁸¹⁵⁹²⁰ is an apocalyptic number.

815920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1142784).

815920 is an abundant number, since it is smaller than the sum of its proper divisors (1469648).

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

815920 is a wasteful number, since it uses less digits than its factorization.

815920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 815920 is about 903.2829014213. The cubic root of 815920 is about 93.4435206577.

The spelling of 815920 in words is "eight hundred fifteen thousand, nine hundred twenty".