815489280 has 216 divisors, whose sum is σ = 2919997080. Its totient is φ = 209879040.

The previous prime is 815489273. The next prime is 815489321. The reversal of 815489280 is 82984518.

It is a happy number.

815489280 is a `hidden beast` number, since 81 + 548 + 9 + 28 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8020224 + 807469056 = 2832^2 + 28416^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 332860 + ... + 335300.

It is an arithmetic number, because the mean of its divisors is an integer number (13518505).

Almost surely, 2^815489280 is an apocalyptic number.

815489280 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 815489280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1459998540).

815489280 is an abundant number, since it is smaller than the sum of its proper divisors (2104507800).

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

815489280 is a wasteful number, since it uses less digits than its factorization.

815489280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2497 (or 2480 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The square root of 815489280 is about 28556.7729269258. The cubic root of 815489280 is about 934.2707497773.

Adding to 815489280 its product of nonzero digits (184320), we get a square (815673600 = 28560²).

The spelling of 815489280 in words is "eight hundred fifteen million, four hundred eighty-nine thousand, two hundred eighty".