21313349 has 2 divisors, whose sum is σ = 21313350. Its totient is φ = 21313348.

The previous prime is 21313343. The next prime is 21313361. The reversal of 21313349 is 94331312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13557124 + 7756225 = 3682^2 + 2785^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313349 - 2⁴ = 21313333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21313343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656674 + 10656675.

It is an arithmetic number, because the mean of its divisors is an integer number (10656675).

Almost surely, 2^21313349 is an apocalyptic number.

It is an amenable number.

21313349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313349 is an equidigital number, since it uses as much as digits as its factorization.

21313349 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 26.

The square root of 21313349 is about 4616.6382790944. The cubic root of 21313349 is about 277.2578804165.

The spelling of 21313349 in words is "twenty-one million, three hundred thirteen thousand, three hundred forty-nine".