663921311 has 4 divisors (see below), whose sum is σ = 664062000. Its totient is φ = 663780624.

The previous prime is 663921287. The next prime is 663921319. The reversal of 663921311 is 113129366.

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 663921311 - 2¹⁸ = 663659167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663921319) 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, 63011 + ... + 72788.

It is an arithmetic number, because the mean of its divisors is an integer number (166015500).

Almost surely, 2^663921311 is an apocalyptic number.

663921311 is a deficient number, since it is larger than the sum of its proper divisors (140689).

663921311 is a wasteful number, since it uses less digits than its factorization.

663921311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140688.

The product of its digits is 5832, while the sum is 32.

The square root of 663921311 is about 25766.6705454935. The cubic root of 663921311 is about 872.3796703814.

The spelling of 663921311 in words is "six hundred sixty-three million, nine hundred twenty-one thousand, three hundred eleven".