660015215 has 4 divisors (see below), whose sum is σ = 792018264. Its totient is φ = 528012168.

The previous prime is 660015197. The next prime is 660015221. The reversal of 660015215 is 512510066.

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

It is a cyclic number.

It is not a de Polignac number, because 660015215 - 2¹² = 660011119 is a prime.

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, 66001517 + ... + 66001526.

It is an arithmetic number, because the mean of its divisors is an integer number (198004566).

Almost surely, 2^660015215 is an apocalyptic number.

660015215 is a deficient number, since it is larger than the sum of its proper divisors (132003049).

660015215 is a wasteful number, since it uses less digits than its factorization.

660015215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132003048.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 660015215 is about 25690.7612771595. The cubic root of 660015215 is about 870.6654595069.

The spelling of 660015215 in words is "six hundred sixty million, fifteen thousand, two hundred fifteen".