21902347 has 2 divisors, whose sum is σ = 21902348. Its totient is φ = 21902346.

The previous prime is 21902339. The next prime is 21902407. The reversal of 21902347 is 74320912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21902347 - 2³ = 21902339 is a prime.

It is not a weakly prime, because it can be changed into another prime (21902317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10951173 + 10951174.

It is an arithmetic number, because the mean of its divisors is an integer number (10951174).

Almost surely, 2^21902347 is an apocalyptic number.

21902347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21902347 is an equidigital number, since it uses as much as digits as its factorization.

21902347 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21902347 is about 4679.9943376034. The cubic root of 21902347 is about 279.7887309369.

The spelling of 21902347 in words is "twenty-one million, nine hundred two thousand, three hundred forty-seven".