664692409 has 8 divisors (see below), whose sum is σ = 715948640. Its totient is φ = 615063456.

The previous prime is 664692373. The next prime is 664692443. The reversal of 664692409 is 904296466.

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

It is a cyclic number.

It is not a de Polignac number, because 664692409 - 2¹³ = 664684217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664698409) 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, 405972 + ... + 407605.

It is an arithmetic number, because the mean of its divisors is an integer number (89493580).

Almost surely, 2^664692409 is an apocalyptic number.

It is an amenable number.

664692409 is a deficient number, since it is larger than the sum of its proper divisors (51256231).

664692409 is a wasteful number, since it uses less digits than its factorization.

664692409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813639.

The product of its (nonzero) digits is 559872, while the sum is 46.

The square root of 664692409 is about 25781.6292929675. The cubic root of 664692409 is about 872.7172756309.

The spelling of 664692409 in words is "six hundred sixty-four million, six hundred ninety-two thousand, four hundred nine".