815655400 has 96 divisors (see below), whose sum is σ = 2203073280. Its totient is φ = 275040000.

The previous prime is 815655397. The next prime is 815655403. The reversal of 815655400 is 4556518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (815655397) and next prime (815655403).

It is not an unprimeable number, because it can be changed into a prime (815655403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 80625 + ... + 90175.

It is an arithmetic number, because the mean of its divisors is an integer number (22948680).

Almost surely, 2^815655400 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 815655400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1101536640).

815655400 is an abundant number, since it is smaller than the sum of its proper divisors (1387417880).

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

815655400 is a wasteful number, since it uses less digits than its factorization.

815655400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9635 (or 9626 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 34.

The square root of 815655400 is about 28559.6813707716. The cubic root of 815655400 is about 934.3341843000.

The spelling of 815655400 in words is "eight hundred fifteen million, six hundred fifty-five thousand, four hundred".