664024661 has 4 divisors (see below), whose sum is σ = 665524032. Its totient is φ = 662525292.

The previous prime is 664024591. The next prime is 664024693. The reversal of 664024661 is 166420466.

664024661 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166420466 = 2 ⋅83210233.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664024661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664024261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 749021 + ... + 749906.

It is an arithmetic number, because the mean of its divisors is an integer number (166381008).

Almost surely, 2^664024661 is an apocalyptic number.

It is an amenable number.

664024661 is a deficient number, since it is larger than the sum of its proper divisors (1499371).

664024661 is a wasteful number, since it uses less digits than its factorization.

664024661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499370.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 664024661 is about 25768.6759652102. The cubic root of 664024661 is about 872.4249346618.

The spelling of 664024661 in words is "six hundred sixty-four million, twenty-four thousand, six hundred sixty-one".