21252899 has 2 divisors, whose sum is σ = 21252900. Its totient is φ = 21252898.

The previous prime is 21252893. The next prime is 21252919. The reversal of 21252899 is 99825212.

21252899 is nontrivially palindromic in base 7.

21252899 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21252899 - 2¹⁶ = 21187363 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21252893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626449 + 10626450.

It is an arithmetic number, because the mean of its divisors is an integer number (10626450).

Almost surely, 2^21252899 is an apocalyptic number.

21252899 is a deficient number, since it is larger than the sum of its proper divisors (1).

21252899 is an equidigital number, since it uses as much as digits as its factorization.

21252899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 38.

The square root of 21252899 is about 4610.0866586215. The cubic root of 21252899 is about 276.9955079272.

The spelling of 21252899 in words is "twenty-one million, two hundred fifty-two thousand, eight hundred ninety-nine".