664451901 has 12 divisors (see below), whose sum is σ = 968570460. Its totient is φ = 438903360.

The previous prime is 664451881. The next prime is 664451903. The reversal of 664451901 is 109154466.

664451901 is a `hidden beast` number, since 6 + 644 + 5 + 1 + 9 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 532224900 + 132227001 = 23070^2 + 11499^2 .

It is not a de Polignac number, because 664451901 - 2²⁵ = 630897469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664451903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 337680 + ... + 339641.

It is an arithmetic number, because the mean of its divisors is an integer number (80714205).

Almost surely, 2^664451901 is an apocalyptic number.

It is an amenable number.

664451901 is a deficient number, since it is larger than the sum of its proper divisors (304118559).

664451901 is a wasteful number, since it uses less digits than its factorization.

664451901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677436 (or 677433 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 664451901 is about 25776.9645420092. The cubic root of 664451901 is about 872.6120034757.

The spelling of 664451901 in words is "six hundred sixty-four million, four hundred fifty-one thousand, nine hundred one".