21493349 has 2 divisors, whose sum is σ = 21493350. Its totient is φ = 21493348.

The previous prime is 21493331. The next prime is 21493363. The reversal of 21493349 is 94339412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16120225 + 5373124 = 4015^2 + 2318^2 .

It is a cyclic number.

It is not a de Polignac number, because 21493349 - 2²⁴ = 4716133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21493309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10746674 + 10746675.

It is an arithmetic number, because the mean of its divisors is an integer number (10746675).

Almost surely, 2^21493349 is an apocalyptic number.

It is an amenable number.

21493349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21493349 is an equidigital number, since it uses as much as digits as its factorization.

21493349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 35.

The square root of 21493349 is about 4636.0919964988. The cubic root of 21493349 is about 278.0362123523.

It can be divided in two parts, 21493 and 349, that multiplied together give a palindrome (7501057).

The spelling of 21493349 in words is "twenty-one million, four hundred ninety-three thousand, three hundred forty-nine".