664969370 has 24 divisors (see below), whose sum is σ = 1296103356. Its totient is φ = 245526528.

The previous prime is 664969343. The next prime is 664969379. The reversal of 664969370 is 73969466.

It is a Cunningham number, because it is equal to 25787²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 1 + 664969369 = 1^2 + 25787^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (664969379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 195047 + ... + 198426.

Almost surely, 2^664969370 is an apocalyptic number.

664969370 is a deficient number, since it is larger than the sum of its proper divisors (631133986).

664969370 is a wasteful number, since it uses less digits than its factorization.

664969370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393506 (or 393493 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 50.

The square root of 664969370 is about 25787.0000193896. Note that the first 4 decimals coincide. The cubic root of 664969370 is about 872.8384720833.

The spelling of 664969370 in words is "six hundred sixty-four million, nine hundred sixty-nine thousand, three hundred seventy".