21013459 has 2 divisors, whose sum is σ = 21013460. Its totient is φ = 21013458.

The previous prime is 21013457. The next prime is 21013483. The reversal of 21013459 is 95431012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21013459 - 2¹ = 21013457 is a prime.

Together with 21013457, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21013451) 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, 10506729 + 10506730.

It is an arithmetic number, because the mean of its divisors is an integer number (10506730).

Almost surely, 2^21013459 is an apocalyptic number.

21013459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013459 is an equidigital number, since it uses as much as digits as its factorization.

21013459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21013459 is about 4584.0439570318. The cubic root of 21013459 is about 275.9513453056.

The spelling of 21013459 in words is "twenty-one million, thirteen thousand, four hundred fifty-nine".