21059459 has 2 divisors, whose sum is σ = 21059460. Its totient is φ = 21059458.

The previous prime is 21059453. The next prime is 21059461. The reversal of 21059459 is 95495012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21059459 - 2¹⁶ = 20993923 is a prime.

Together with 21059461, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21059453) 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, 10529729 + 10529730.

It is an arithmetic number, because the mean of its divisors is an integer number (10529730).

Almost surely, 2^21059459 is an apocalyptic number.

21059459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21059459 is an equidigital number, since it uses as much as digits as its factorization.

21059459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16200, while the sum is 35.

The square root of 21059459 is about 4589.0586180610. The cubic root of 21059459 is about 276.1525577858.

The spelling of 21059459 in words is "twenty-one million, fifty-nine thousand, four hundred fifty-nine".