664240465 has 16 divisors (see below), whose sum is σ = 935580672. Its totient is φ = 443168064.

The previous prime is 664240433. The next prime is 664240469. The reversal of 664240465 is 564042466.

It is a cyclic number.

It is not a de Polignac number, because 664240465 - 2⁵ = 664240433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664240469) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255169 + ... + 257758.

It is an arithmetic number, because the mean of its divisors is an integer number (58473792).

Almost surely, 2^664240465 is an apocalyptic number.

It is an amenable number.

664240465 is a deficient number, since it is larger than the sum of its proper divisors (271340207).

664240465 is a wasteful number, since it uses less digits than its factorization.

664240465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512976.

The product of its (nonzero) digits is 138240, while the sum is 37.

The square root of 664240465 is about 25772.8629569941. The cubic root of 664240465 is about 872.5194353681.

The spelling of 664240465 in words is "six hundred sixty-four million, two hundred forty thousand, four hundred sixty-five".