21492259 has 2 divisors, whose sum is σ = 21492260. Its totient is φ = 21492258.

The previous prime is 21492257. The next prime is 21492349. The reversal of 21492259 is 95229412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21492259 - 2¹ = 21492257 is a prime.

Together with 21492257, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21492257) 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, 10746129 + 10746130.

It is an arithmetic number, because the mean of its divisors is an integer number (10746130).

Almost surely, 2^21492259 is an apocalyptic number.

21492259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21492259 is an equidigital number, since it uses as much as digits as its factorization.

21492259 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 34.

The square root of 21492259 is about 4635.9744391012. The cubic root of 21492259 is about 278.0315122224.

The spelling of 21492259 in words is "twenty-one million, four hundred ninety-two thousand, two hundred fifty-nine".