21633023 has 2 divisors, whose sum is σ = 21633024. Its totient is φ = 21633022.

The previous prime is 21633011. The next prime is 21633047. The reversal of 21633023 is 32033612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21633023 - 2¹⁶ = 21567487 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21632986 and 21633004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21633083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10816511 + 10816512.

It is an arithmetic number, because the mean of its divisors is an integer number (10816512).

Almost surely, 2^21633023 is an apocalyptic number.

21633023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21633023 is an equidigital number, since it uses as much as digits as its factorization.

21633023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 20.

The square root of 21633023 is about 4651.1313677427. The cubic root of 21633023 is about 278.6371829252.

Adding to 21633023 its reverse (32033612), we get a palindrome (53666635).

The spelling of 21633023 in words is "twenty-one million, six hundred thirty-three thousand, twenty-three".