21847349 has 2 divisors, whose sum is σ = 21847350. Its totient is φ = 21847348.

The previous prime is 21847303. The next prime is 21847351. The reversal of 21847349 is 94374812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15547249 + 6300100 = 3943^2 + 2510^2 .

It is a cyclic number.

It is not a de Polignac number, because 21847349 - 2²⁴ = 5070133 is a prime.

Together with 21847351, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21847369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10923674 + 10923675.

It is an arithmetic number, because the mean of its divisors is an integer number (10923675).

Almost surely, 2^21847349 is an apocalyptic number.

It is an amenable number.

21847349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21847349 is an equidigital number, since it uses as much as digits as its factorization.

21847349 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 38.

The square root of 21847349 is about 4674.1147825016. The cubic root of 21847349 is about 279.5543463370.

The spelling of 21847349 in words is "twenty-one million, eight hundred forty-seven thousand, three hundred forty-nine".