21349459 has 2 divisors, whose sum is σ = 21349460. Its totient is φ = 21349458.

The previous prime is 21349453. The next prime is 21349511. The reversal of 21349459 is 95494312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21349459 - 2¹⁷ = 21218387 is a prime.

It is not a weakly prime, because it can be changed into another prime (21349453) 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, 10674729 + 10674730.

It is an arithmetic number, because the mean of its divisors is an integer number (10674730).

Almost surely, 2^21349459 is an apocalyptic number.

21349459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21349459 is an equidigital number, since it uses as much as digits as its factorization.

21349459 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 21349459 is about 4620.5474783839. The cubic root of 21349459 is about 277.4143728452.

The spelling of 21349459 in words is "twenty-one million, three hundred forty-nine thousand, four hundred fifty-nine".