633872021 has 2 divisors, whose sum is σ = 633872022. Its totient is φ = 633872020.

The previous prime is 633872017. The next prime is 633872039. The reversal of 633872021 is 120278336.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 629508100 + 4363921 = 25090^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 633872021 - 2² = 633872017 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (633872321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 316936010 + 316936011.

It is an arithmetic number, because the mean of its divisors is an integer number (316936011).

Almost surely, 2^633872021 is an apocalyptic number.

It is an amenable number.

633872021 is a deficient number, since it is larger than the sum of its proper divisors (1).

633872021 is an equidigital number, since it uses as much as digits as its factorization.

633872021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 633872021 is about 25176.8151480683. The cubic root of 633872021 is about 859.0145648839.

The spelling of 633872021 in words is "six hundred thirty-three million, eight hundred seventy-two thousand, twenty-one".