815521464 has 48 divisors (see below), whose sum is σ = 2279958720. Its totient is φ = 263070720.

The previous prime is 815521463. The next prime is 815521489. The reversal of 815521464 is 464125518.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815521463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180457 + ... + 184920.

It is an arithmetic number, because the mean of its divisors is an integer number (47499140).

Almost surely, 2^815521464 is an apocalyptic number.

It is an amenable number.

815521464 is an abundant number, since it is smaller than the sum of its proper divisors (1464437256).

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

815521464 is a wasteful number, since it uses less digits than its factorization.

815521464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365420 (or 365413 counting only the distinct ones).

The product of its digits is 38400, while the sum is 36.

The square root of 815521464 is about 28557.3364304166. The cubic root of 815521464 is about 934.2830402206.

The spelling of 815521464 in words is "eight hundred fifteen million, five hundred twenty-one thousand, four hundred sixty-four".