633040021 has 2 divisors, whose sum is σ = 633040022. Its totient is φ = 633040020.

The previous prime is 633040019. The next prime is 633040061. The reversal of 633040021 is 120040336.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 619312996 + 13727025 = 24886^2 + 3705^2 .

It is a cyclic number.

It is not a de Polignac number, because 633040021 - 2¹ = 633040019 is a prime.

Together with 633040019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (633040061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 316520010 + 316520011.

It is an arithmetic number, because the mean of its divisors is an integer number (316520011).

Almost surely, 2^633040021 is an apocalyptic number.

It is an amenable number.

633040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

633040021 is an equidigital number, since it uses as much as digits as its factorization.

633040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 633040021 is about 25160.2865842184. The cubic root of 633040021 is about 858.6385620421.

Adding to 633040021 its reverse (120040336), we get a palindrome (753080357).

The spelling of 633040021 in words is "six hundred thirty-three million, forty thousand, twenty-one".