815220385 has 8 divisors (see below), whose sum is σ = 1118016576. Its totient is φ = 559008240.

The previous prime is 815220377. The next prime is 815220407. The reversal of 815220385 is 583022518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 815220385 - 2³ = 815220377 is a prime.

It is a super-2 number, since 2×815220385² = 1329168552239096450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 815220385.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11645971 + ... + 11646040.

It is an arithmetic number, because the mean of its divisors is an integer number (139752072).

Almost surely, 2^815220385 is an apocalyptic number.

It is an amenable number.

815220385 is a deficient number, since it is larger than the sum of its proper divisors (302796191).

815220385 is a wasteful number, since it uses less digits than its factorization.

815220385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23292023.

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 815220385 is about 28552.0644612609. The cubic root of 815220385 is about 934.1680513702.

The spelling of 815220385 in words is "eight hundred fifteen million, two hundred twenty thousand, three hundred eighty-five".