664215345 has 24 divisors (see below), whose sum is σ = 1173033576. Its totient is φ = 347563008.

The previous prime is 664215323. The next prime is 664215361. The reversal of 664215345 is 543512466.

664215345 is a `hidden beast` number, since 6 + 642 + 1 + 5 + 3 + 4 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 255488256 + 408727089 = 15984^2 + 20217^2 .

It is not a de Polignac number, because 664215345 - 2⁹ = 664214833 is a prime.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 136864 + ... + 141633.

It is an arithmetic number, because the mean of its divisors is an integer number (48876399).

Almost surely, 2^664215345 is an apocalyptic number.

It is an amenable number.

664215345 is a deficient number, since it is larger than the sum of its proper divisors (508818231).

664215345 is a wasteful number, since it uses less digits than its factorization.

664215345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278561 (or 278558 counting only the distinct ones).

The product of its digits is 86400, while the sum is 36.

The square root of 664215345 is about 25772.3756180916. The cubic root of 664215345 is about 872.5084363571.

The spelling of 664215345 in words is "six hundred sixty-four million, two hundred fifteen thousand, three hundred forty-five".