663122721 has 8 divisors (see below), whose sum is σ = 886058784. Its totient is φ = 441134240.

The previous prime is 663122711. The next prime is 663122731. The reversal of 663122721 is 127221366.

It is an interprime number because it is at equal distance from previous prime (663122711) and next prime (663122731).

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 663122721 - 2⁶ = 663122657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (663122701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235260 + ... + 238061.

It is an arithmetic number, because the mean of its divisors is an integer number (110757348).

Almost surely, 2^663122721 is an apocalyptic number.

It is an amenable number.

663122721 is a deficient number, since it is larger than the sum of its proper divisors (222936063).

663122721 is a wasteful number, since it uses less digits than its factorization.

663122721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473791.

The product of its digits is 6048, while the sum is 30.

The square root of 663122721 is about 25751.1693132564. The cubic root of 663122721 is about 872.0297528110.

The spelling of 663122721 in words is "six hundred sixty-three million, one hundred twenty-two thousand, seven hundred twenty-one".