815550400 has 84 divisors (see below), whose sum is σ = 2293475728. Its totient is φ = 279613440.

The previous prime is 815550397. The next prime is 815550403. The reversal of 815550400 is 4055518.

It is an interprime number because it is at equal distance from previous prime (815550397) and next prime (815550403).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815550403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25209 + ... + 47608.

Almost surely, 2^815550400 is an apocalyptic number.

815550400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

815550400 is an abundant number, since it is smaller than the sum of its proper divisors (1477925328).

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

815550400 is a wasteful number, since it uses less digits than its factorization.

815550400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72846 (or 72831 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 815550400 is about 28557.8430558052. The cubic root of 815550400 is about 934.2940900399.

The spelling of 815550400 in words is "eight hundred fifteen million, five hundred fifty thousand, four hundred".