664831509 has 8 divisors (see below), whose sum is σ = 891750720. Its totient is φ = 440566656.

The previous prime is 664831493. The next prime is 664831543. The reversal of 664831509 is 905138466.

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

It is not a de Polignac number, because 664831509 - 2⁴ = 664831493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664831589) 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, 663004 + ... + 664005.

It is an arithmetic number, because the mean of its divisors is an integer number (111468840).

Almost surely, 2^664831509 is an apocalyptic number.

It is an amenable number.

664831509 is a deficient number, since it is larger than the sum of its proper divisors (226919211).

664831509 is a wasteful number, since it uses less digits than its factorization.

664831509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327179.

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 664831509 is about 25784.3268091296. The cubic root of 664831509 is about 872.7781491539.

The spelling of 664831509 in words is "six hundred sixty-four million, eight hundred thirty-one thousand, five hundred nine".