664997065 has 4 divisors (see below), whose sum is σ = 797996484. Its totient is φ = 531997648.

The previous prime is 664997059. The next prime is 664997071. The reversal of 664997065 is 560799466.

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

It is an interprime number because it is at equal distance from previous prime (664997059) and next prime (664997071).

It can be written as a sum of positive squares in 2 ways, for example, as 461906064 + 203091001 = 21492^2 + 14251^2 .

It is a cyclic number.

It is not a de Polignac number, because 664997065 - 2⁵ = 664997033 is a prime.

It is a super-2 number, since 2×664997065² = 884442192917228450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66499702 + ... + 66499711.

It is an arithmetic number, because the mean of its divisors is an integer number (199499121).

Almost surely, 2^664997065 is an apocalyptic number.

It is an amenable number.

664997065 is a deficient number, since it is larger than the sum of its proper divisors (132999419).

664997065 is a wasteful number, since it uses less digits than its factorization.

664997065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132999418.

The product of its (nonzero) digits is 2449440, while the sum is 52.

The square root of 664997065 is about 25787.5370091833. The cubic root of 664997065 is about 872.8505893963.

The spelling of 664997065 in words is "six hundred sixty-four million, nine hundred ninety-seven thousand, sixty-five".