815321088 has 156 divisors (see below), whose sum is σ = 2495535588. Its totient is φ = 255590400.

The previous prime is 815321081. The next prime is 815321093. The reversal of 815321088 is 880123518.

It can be written as a sum of positive squares in 2 ways, for example, as 230068224 + 585252864 = 15168^2 + 24192^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815321081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 626038 + ... + 627338.

It is an arithmetic number, because the mean of its divisors is an integer number (15997023).

Almost surely, 2^815321088 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 815321088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1247767794).

815321088 is an abundant number, since it is smaller than the sum of its proper divisors (1680214500).

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

815321088 is a wasteful number, since it uses less digits than its factorization.

815321088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348 (or 1323 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 815321088 is about 28553.8279045035. The cubic root of 815321088 is about 934.2065152644.

It can be divided in two parts, 8153 and 21088, that added together give a square (29241 = 171²).

The spelling of 815321088 in words is "eight hundred fifteen million, three hundred twenty-one thousand, eighty-eight".