655991915 has 4 divisors (see below), whose sum is σ = 787190304. Its totient is φ = 524793528.

The previous prime is 655991909. The next prime is 655991927. The reversal of 655991915 is 519199556.

It is a happy number.

655991915 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 655991915 - 2⁶ = 655991851 is a prime.

It is a Duffinian 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, 65599187 + ... + 65599196.

It is an arithmetic number, because the mean of its divisors is an integer number (196797576).

Almost surely, 2^655991915 is an apocalyptic number.

655991915 is a deficient number, since it is larger than the sum of its proper divisors (131198389).

655991915 is a wasteful number, since it uses less digits than its factorization.

655991915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131198388.

The product of its digits is 546750, while the sum is 50.

The square root of 655991915 is about 25612.3391161370. The cubic root of 655991915 is about 868.8927275117.

The spelling of 655991915 in words is "six hundred fifty-five million, nine hundred ninety-one thousand, nine hundred fifteen".