21298307 has 2 divisors, whose sum is σ = 21298308. Its totient is φ = 21298306.

The previous prime is 21298283. The next prime is 21298309. The reversal of 21298307 is 70389212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21298307 - 2¹⁸ = 21036163 is a prime.

Together with 21298309, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21298309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649153 + 10649154.

It is an arithmetic number, because the mean of its divisors is an integer number (10649154).

Almost surely, 2^21298307 is an apocalyptic number.

21298307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21298307 is an equidigital number, since it uses as much as digits as its factorization.

21298307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 21298307 is about 4615.0088840651. The cubic root of 21298307 is about 277.1926396990.

The spelling of 21298307 in words is "twenty-one million, two hundred ninety-eight thousand, three hundred seven".