664565426 has 16 divisors (see below), whose sum is σ = 1139623296. Its totient is φ = 284721696.

The previous prime is 664565423. The next prime is 664565431. The reversal of 664565426 is 624565466.

It is a happy number.

It is a super-2 number, since 2×664565426² = 883294410869122952, which contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (664565423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54635 + ... + 65681.

It is an arithmetic number, because the mean of its divisors is an integer number (71226456).

Almost surely, 2^664565426 is an apocalyptic number.

664565426 is a deficient number, since it is larger than the sum of its proper divisors (475057870).

664565426 is a wasteful number, since it uses less digits than its factorization.

664565426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15353.

The product of its digits is 1036800, while the sum is 44.

The square root of 664565426 is about 25779.1665109638. The cubic root of 664565426 is about 872.6616973844.

The spelling of 664565426 in words is "six hundred sixty-four million, five hundred sixty-five thousand, four hundred twenty-six".