815216015 has 4 divisors (see below), whose sum is σ = 978259224. Its totient is φ = 652172808.

The previous prime is 815216009. The next prime is 815216027. The reversal of 815216015 is 510612518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815216015 is a prime.

It is a super-2 number, since 2×815216015² = 1329154302224960450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81521597 + ... + 81521606.

It is an arithmetic number, because the mean of its divisors is an integer number (244564806).

Almost surely, 2^815216015 is an apocalyptic number.

815216015 is a deficient number, since it is larger than the sum of its proper divisors (163043209).

815216015 is a wasteful number, since it uses less digits than its factorization.

815216015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163043208.

The product of its (nonzero) digits is 2400, while the sum is 29.

The square root of 815216015 is about 28551.9879342928. The cubic root of 815216015 is about 934.1663821603.

The spelling of 815216015 in words is "eight hundred fifteen million, two hundred sixteen thousand, fifteen".