21525199 has 2 divisors, whose sum is σ = 21525200. Its totient is φ = 21525198.

The previous prime is 21525197. The next prime is 21525223. The reversal of 21525199 is 99152512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21525199 - 2¹ = 21525197 is a prime.

Together with 21525197, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21525197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762599 + 10762600.

It is an arithmetic number, because the mean of its divisors is an integer number (10762600).

Almost surely, 2^21525199 is an apocalyptic number.

21525199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21525199 is an equidigital number, since it uses as much as digits as its factorization.

21525199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8100, while the sum is 34.

The square root of 21525199 is about 4639.5257300720. The cubic root of 21525199 is about 278.1734809060.

The spelling of 21525199 in words is "twenty-one million, five hundred twenty-five thousand, one hundred ninety-nine".