21335549 has 2 divisors, whose sum is σ = 21335550. Its totient is φ = 21335548.

The previous prime is 21335519. The next prime is 21335557. The reversal of 21335549 is 94553312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12124324 + 9211225 = 3482^2 + 3035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21335549 is a prime.

It is a super-2 number, since 2×21335549² = 910411302262802, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667774 + 10667775.

It is an arithmetic number, because the mean of its divisors is an integer number (10667775).

Almost surely, 2^21335549 is an apocalyptic number.

It is an amenable number.

21335549 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335549 is an equidigital number, since it uses as much as digits as its factorization.

21335549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16200, while the sum is 32.

The square root of 21335549 is about 4619.0420002420. The cubic root of 21335549 is about 277.3541110170.

The spelling of 21335549 in words is "twenty-one million, three hundred thirty-five thousand, five hundred forty-nine".