664633408531 has 4 divisors (see below), whose sum is σ = 665651224512. Its totient is φ = 663615592552.

The previous prime is 664633408529. The next prime is 664633408553. The reversal of 664633408531 is 135804336466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664633408531 - 2¹ = 664633408529 is a prime.

It is a super-2 number, since 2×664633408531² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664633408511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 508907011 + ... + 508908316.

It is an arithmetic number, because the mean of its divisors is an integer number (166412806128).

Almost surely, 2^664633408531 is an apocalyptic number.

664633408531 is a deficient number, since it is larger than the sum of its proper divisors (1017815981).

664633408531 is a wasteful number, since it uses less digits than its factorization.

664633408531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017815980.

The product of its (nonzero) digits is 3732480, while the sum is 49.

The spelling of 664633408531 in words is "six hundred sixty-four billion, six hundred thirty-three million, four hundred eight thousand, five hundred thirty-one".