664731637 has 8 divisors (see below), whose sum is σ = 704794176. Its totient is φ = 624775872.

The previous prime is 664731631. The next prime is 664731659. The reversal of 664731637 is 736137466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664731637 - 2³ = 664731629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664731593 and 664731602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664731631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13683 + ... + 38944.

It is an arithmetic number, because the mean of its divisors is an integer number (88099272).

Almost surely, 2^664731637 is an apocalyptic number.

It is an amenable number.

664731637 is a deficient number, since it is larger than the sum of its proper divisors (40062539).

664731637 is a wasteful number, since it uses less digits than its factorization.

664731637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53387.

The product of its digits is 381024, while the sum is 43.

The square root of 664731637 is about 25782.3900560053. The cubic root of 664731637 is about 872.7344436118.

The spelling of 664731637 in words is "six hundred sixty-four million, seven hundred thirty-one thousand, six hundred thirty-seven".