664975511 has 4 divisors (see below), whose sum is σ = 665588352. Its totient is φ = 664362672.

The previous prime is 664975501. The next prime is 664975523. The reversal of 664975511 is 115579466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664975511 - 2⁶ = 664975447 is a prime.

It is a super-2 number, since 2×664975511² = 884384860459422242, 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 (664975501) 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, 304790 + ... + 306963.

It is an arithmetic number, because the mean of its divisors is an integer number (166397088).

Almost surely, 2^664975511 is an apocalyptic number.

664975511 is a deficient number, since it is larger than the sum of its proper divisors (612841).

664975511 is a wasteful number, since it uses less digits than its factorization.

664975511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612840.

The product of its digits is 226800, while the sum is 44.

The square root of 664975511 is about 25787.1190907399. The cubic root of 664975511 is about 872.8411589663.

The spelling of 664975511 in words is "six hundred sixty-four million, nine hundred seventy-five thousand, five hundred eleven".