664671537 has 12 divisors (see below), whose sum is σ = 968578884. Its totient is φ = 439192320.

The previous prime is 664671517. The next prime is 664671551. The reversal of 664671537 is 735176466.

664671537 is a `hidden beast` number, since 6 + 6 + 46 + 71 + 537 = 666.

664671537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 15492096 + 649179441 = 3936^2 + 25479^2 .

It is not a de Polignac number, because 664671537 - 2⁶ = 664671473 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664671492 and 664671501.

It is not an unprimeable number, because it can be changed into a prime (664671517) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 325764 + ... + 327797.

It is an arithmetic number, because the mean of its divisors is an integer number (80714907).

Almost surely, 2^664671537 is an apocalyptic number.

It is an amenable number.

664671537 is a deficient number, since it is larger than the sum of its proper divisors (303907347).

664671537 is a wasteful number, since it uses less digits than its factorization.

664671537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653680 (or 653677 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The square root of 664671537 is about 25781.2245054419. The cubic root of 664671537 is about 872.7081408063.

The spelling of 664671537 in words is "six hundred sixty-four million, six hundred seventy-one thousand, five hundred thirty-seven".