663936947 has 4 divisors (see below), whose sum is σ = 665436120. Its totient is φ = 662437776.

The previous prime is 663936941. The next prime is 663936983. The reversal of 663936947 is 749639366.

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 663936947 - 2²⁰ = 662888371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663936941) 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 3 ways as a sum of consecutive naturals, for example, 748922 + ... + 749807.

It is an arithmetic number, because the mean of its divisors is an integer number (166359030).

Almost surely, 2^663936947 is an apocalyptic number.

663936947 is a deficient number, since it is larger than the sum of its proper divisors (1499173).

663936947 is a wasteful number, since it uses less digits than its factorization.

663936947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499172.

The product of its digits is 4408992, while the sum is 53.

The square root of 663936947 is about 25766.9739589266. The cubic root of 663936947 is about 872.3865187941.

The spelling of 663936947 in words is "six hundred sixty-three million, nine hundred thirty-six thousand, nine hundred forty-seven".