663989801 has 4 divisors (see below), whose sum is σ = 664109952. Its totient is φ = 663869652.

The previous prime is 663989797. The next prime is 663989813. The reversal of 663989801 is 108989366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 663989801 - 2² = 663989797 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 663989801.

It is not an unprimeable number, because it can be changed into a prime (663989831) 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, 51365 + ... + 62978.

It is an arithmetic number, because the mean of its divisors is an integer number (166027488).

Almost surely, 2^663989801 is an apocalyptic number.

It is an amenable number.

663989801 is a deficient number, since it is larger than the sum of its proper divisors (120151).

663989801 is a wasteful number, since it uses less digits than its factorization.

663989801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120150.

The product of its (nonzero) digits is 559872, while the sum is 50.

The square root of 663989801 is about 25767.9995537100. Note that the first 3 decimals coincide. The cubic root of 663989801 is about 872.4096675252.

The spelling of 663989801 in words is "six hundred sixty-three million, nine hundred eighty-nine thousand, eight hundred one".