664176661 has 4 divisors (see below), whose sum is σ = 664500672. Its totient is φ = 663852652.

The previous prime is 664176659. The next prime is 664176679. The reversal of 664176661 is 166671466.

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.

It is a cyclic number.

It is not a de Polignac number, because 664176661 - 2¹ = 664176659 is a prime.

It is a super-2 number, since 2×664176661² = 882261274034217842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664176631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158911 + ... + 163036.

It is an arithmetic number, because the mean of its divisors is an integer number (166125168).

Almost surely, 2^664176661 is an apocalyptic number.

It is an amenable number.

664176661 is a deficient number, since it is larger than the sum of its proper divisors (324011).

664176661 is a wasteful number, since it uses less digits than its factorization.

664176661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324010.

The product of its digits is 217728, while the sum is 43.

The square root of 664176661 is about 25771.6251136788. The cubic root of 664176661 is about 872.4914976881.

The spelling of 664176661 in words is "six hundred sixty-four million, one hundred seventy-six thousand, six hundred sixty-one".