815321478 has 16 divisors (see below), whose sum is σ = 1630923840. Its totient is φ = 271727016.

The previous prime is 815321477. The next prime is 815321501. The reversal of 815321478 is 874123518.

It is a super-2 number, since 2×815321478² = 1329498224976208968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815321473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57633 + ... + 70371.

It is an arithmetic number, because the mean of its divisors is an integer number (101932740).

Almost surely, 2^815321478 is an apocalyptic number.

815321478 is an abundant number, since it is smaller than the sum of its proper divisors (815602362).

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

815321478 is a wasteful number, since it uses less digits than its factorization.

815321478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23411.

The product of its digits is 53760, while the sum is 39.

The square root of 815321478 is about 28553.8347337096. The cubic root of 815321478 is about 934.2066642202.

The spelling of 815321478 in words is "eight hundred fifteen million, three hundred twenty-one thousand, four hundred seventy-eight".