21797233 has 2 divisors, whose sum is σ = 21797234. Its totient is φ = 21797232.

The previous prime is 21797207. The next prime is 21797249. The reversal of 21797233 is 33279712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21372129 + 425104 = 4623^2 + 652^2 .

It is a cyclic number.

It is not a de Polignac number, because 21797233 - 2⁵ = 21797201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21797203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10898616 + 10898617.

It is an arithmetic number, because the mean of its divisors is an integer number (10898617).

Almost surely, 2^21797233 is an apocalyptic number.

It is an amenable number.

21797233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21797233 is an equidigital number, since it uses as much as digits as its factorization.

21797233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 34.

The square root of 21797233 is about 4668.7506894243. The cubic root of 21797233 is about 279.3404245473.

The spelling of 21797233 in words is "twenty-one million, seven hundred ninety-seven thousand, two hundred thirty-three".