21335449 has 2 divisors, whose sum is σ = 21335450. Its totient is φ = 21335448.

The previous prime is 21335437. The next prime is 21335453. The reversal of 21335449 is 94453312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11526025 + 9809424 = 3395^2 + 3132^2 .

It is a cyclic number.

It is not a de Polignac number, because 21335449 - 2¹⁵ = 21302681 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21335449.

It is not a weakly prime, because it can be changed into another prime (21335549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667724 + 10667725.

It is an arithmetic number, because the mean of its divisors is an integer number (10667725).

Almost surely, 2^21335449 is an apocalyptic number.

It is an amenable number.

21335449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335449 is an equidigital number, since it uses as much as digits as its factorization.

21335449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 31.

The square root of 21335449 is about 4619.0311754739. The cubic root of 21335449 is about 277.3536776955.

The spelling of 21335449 in words is "twenty-one million, three hundred thirty-five thousand, four hundred forty-nine".