664956491 has 8 divisors (see below), whose sum is σ = 692722800. Its totient is φ = 637740160.

The previous prime is 664956463. The next prime is 664956503. The reversal of 664956491 is 194659466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664956491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664956421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135026 + ... + 139863.

It is an arithmetic number, because the mean of its divisors is an integer number (86590350).

Almost surely, 2^664956491 is an apocalyptic number.

664956491 is a deficient number, since it is larger than the sum of its proper divisors (27766309).

664956491 is a wasteful number, since it uses less digits than its factorization.

664956491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274989.

The product of its digits is 1399680, while the sum is 50.

The square root of 664956491 is about 25786.7502993301. The cubic root of 664956491 is about 872.8328370572.

The spelling of 664956491 in words is "six hundred sixty-four million, nine hundred fifty-six thousand, four hundred ninety-one".