664621215 has 16 divisors (see below), whose sum is σ = 1070439936. Its totient is φ = 352116000.

The previous prime is 664621211. The next prime is 664621241. The reversal of 664621215 is 512126466.

It is not a de Polignac number, because 664621215 - 2² = 664621211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664621211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144451 + ... + 148980.

It is an arithmetic number, because the mean of its divisors is an integer number (66902496).

Almost surely, 2^664621215 is an apocalyptic number.

664621215 is a deficient number, since it is larger than the sum of its proper divisors (405818721).

664621215 is a wasteful number, since it uses less digits than its factorization.

664621215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293590.

The product of its digits is 17280, while the sum is 33.

The square root of 664621215 is about 25780.2485441859. The cubic root of 664621215 is about 872.6861161295.

The spelling of 664621215 in words is "six hundred sixty-four million, six hundred twenty-one thousand, two hundred fifteen".