815149440 has 512 divisors, whose sum is σ = 3454617600. Its totient is φ = 177610752.

The previous prime is 815149427. The next prime is 815149451. The reversal of 815149440 is 44941518.

815149440 is a `hidden beast` number, since 81 + 51 + 494 + 40 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a junction number, because it is equal to n+sod(n) for n = 815149395 and 815149404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2781934 + ... + 2782226.

It is an arithmetic number, because the mean of its divisors is an integer number (6747300).

Almost surely, 2^815149440 is an apocalyptic number.

815149440 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 815149440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1727308800).

815149440 is an abundant number, since it is smaller than the sum of its proper divisors (2639468160).

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

815149440 is a wasteful number, since it uses less digits than its factorization.

815149440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 815149440 is about 28550.8220547150. The cubic root of 815149440 is about 934.1409517555.

The spelling of 815149440 in words is "eight hundred fifteen million, one hundred forty-nine thousand, four hundred forty".