21910307 has 2 divisors, whose sum is σ = 21910308. Its totient is φ = 21910306.

The previous prime is 21910289. The next prime is 21910309. The reversal of 21910307 is 70301912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21910307 - 2²⁴ = 5133091 is a prime.

Together with 21910309, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21910309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10955153 + 10955154.

It is an arithmetic number, because the mean of its divisors is an integer number (10955154).

Almost surely, 2^21910307 is an apocalyptic number.

21910307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21910307 is an equidigital number, since it uses as much as digits as its factorization.

21910307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 21910307 is about 4680.8446887287. The cubic root of 21910307 is about 279.8226214989.

The spelling of 21910307 in words is "twenty-one million, nine hundred ten thousand, three hundred seven".