21397301 has 2 divisors, whose sum is σ = 21397302. Its totient is φ = 21397300.

The previous prime is 21397297. The next prime is 21397303. The reversal of 21397301 is 10379312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20016676 + 1380625 = 4474^2 + 1175^2 .

It is a cyclic number.

It is not a de Polignac number, because 21397301 - 2² = 21397297 is a prime.

It is a Sophie Germain prime.

Together with 21397303, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21397303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10698650 + 10698651.

It is an arithmetic number, because the mean of its divisors is an integer number (10698651).

Almost surely, 2^21397301 is an apocalyptic number.

It is an amenable number.

21397301 is a deficient number, since it is larger than the sum of its proper divisors (1).

21397301 is an equidigital number, since it uses as much as digits as its factorization.

21397301 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 21397301 is about 4625.7216734257. The cubic root of 21397301 is about 277.6214375295.

The spelling of 21397301 in words is "twenty-one million, three hundred ninety-seven thousand, three hundred one".