21432233 has 2 divisors, whose sum is σ = 21432234. Its totient is φ = 21432232.

The previous prime is 21432211. The next prime is 21432239. The reversal of 21432233 is 33223412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21409129 + 23104 = 4627^2 + 152^2 .

It is a cyclic number.

It is not a de Polignac number, because 21432233 - 2¹⁰ = 21431209 is a prime.

It is a super-2 number, since 2×21432233² = 918681222732578, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21432239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716116 + 10716117.

It is an arithmetic number, because the mean of its divisors is an integer number (10716117).

Almost surely, 2^21432233 is an apocalyptic number.

It is an amenable number.

21432233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21432233 is an equidigital number, since it uses as much as digits as its factorization.

21432233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 20.

The square root of 21432233 is about 4629.4959768856. The cubic root of 21432233 is about 277.7724316423.

Adding to 21432233 its reverse (33223412), we get a palindrome (54655645).

The spelling of 21432233 in words is "twenty-one million, four hundred thirty-two thousand, two hundred thirty-three".