21898433 has 2 divisors, whose sum is σ = 21898434. Its totient is φ = 21898432.

The previous prime is 21898417. The next prime is 21898441. The reversal of 21898433 is 33489812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21836929 + 61504 = 4673^2 + 248^2 .

It is a cyclic number.

It is not a de Polignac number, because 21898433 - 2⁴ = 21898417 is a prime.

It is not a weakly prime, because it can be changed into another prime (21898403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10949216 + 10949217.

It is an arithmetic number, because the mean of its divisors is an integer number (10949217).

Almost surely, 2^21898433 is an apocalyptic number.

It is an amenable number.

21898433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21898433 is an equidigital number, since it uses as much as digits as its factorization.

21898433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 38.

The square root of 21898433 is about 4679.5761560210. The cubic root of 21898433 is about 279.7720636465.

The spelling of 21898433 in words is "twenty-one million, eight hundred ninety-eight thousand, four hundred thirty-three".