21855349 has 2 divisors, whose sum is σ = 21855350. Its totient is φ = 21855348.

The previous prime is 21855343. The next prime is 21855367. The reversal of 21855349 is 94355812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12552849 + 9302500 = 3543^2 + 3050^2 .

It is a cyclic number.

It is not a de Polignac number, because 21855349 - 2⁹ = 21854837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21855343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927674 + 10927675.

It is an arithmetic number, because the mean of its divisors is an integer number (10927675).

Almost surely, 2^21855349 is an apocalyptic number.

It is an amenable number.

21855349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21855349 is an equidigital number, since it uses as much as digits as its factorization.

21855349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 37.

The square root of 21855349 is about 4674.9704811902. The cubic root of 21855349 is about 279.5884643109.

The spelling of 21855349 in words is "twenty-one million, eight hundred fifty-five thousand, three hundred forty-nine".