21852197 has 2 divisors, whose sum is σ = 21852198. Its totient is φ = 21852196.

The previous prime is 21852169. The next prime is 21852203. The reversal of 21852197 is 79125812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20349121 + 1503076 = 4511^2 + 1226^2 .

It is a cyclic number.

It is not a de Polignac number, because 21852197 - 2²⁰ = 20803621 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21852137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10926098 + 10926099.

It is an arithmetic number, because the mean of its divisors is an integer number (10926099).

Almost surely, 2^21852197 is an apocalyptic number.

It is an amenable number.

21852197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21852197 is an equidigital number, since it uses as much as digits as its factorization.

21852197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 35.

The square root of 21852197 is about 4674.6333546065. The cubic root of 21852197 is about 279.5750228233.

The spelling of 21852197 in words is "twenty-one million, eight hundred fifty-two thousand, one hundred ninety-seven".