815445136 has 75 divisors (see below), whose sum is σ = 1767861955. Its totient is φ = 364374560.

The previous prime is 815445107. The next prime is 815445139. The reversal of 815445136 is 631544518.

It is a happy number.

The square root of 815445136 is 28556.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

Its product of digits (57600) is a multiple of the sum of its prime divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 815445095 and 815445104.

It is not an unprimeable number, because it can be changed into a prime (815445139) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 13821075 + ... + 13821133.

Almost surely, 2^815445136 is an apocalyptic number.

815445136 is the 28556-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815445136

815445136 is an abundant number, since it is smaller than the sum of its proper divisors (952416819).

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

815445136 is an frugal number, since it uses more digits than its factorization.

815445136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 72 counting only the distinct ones).

The product of its digits is 57600, while the sum is 37.

The cubic root of 815445136 is about 934.2538915168.

Multiplying 815445136 by its product of digits (57600), we get a square (46969639833600 = 6853440²).

The spelling of 815445136 in words is "eight hundred fifteen million, four hundred forty-five thousand, one hundred thirty-six".