21903241 has 2 divisors, whose sum is σ = 21903242. Its totient is φ = 21903240.

The previous prime is 21903229. The next prime is 21903247. The reversal of 21903241 is 14230912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21902400 + 841 = 4680^2 + 29^2 .

It is a cyclic number.

It is not a de Polignac number, because 21903241 - 2⁷ = 21903113 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21903247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10951620 + 10951621.

It is an arithmetic number, because the mean of its divisors is an integer number (10951621).

Almost surely, 2^21903241 is an apocalyptic number.

It is an amenable number.

21903241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21903241 is an equidigital number, since it uses as much as digits as its factorization.

21903241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21903241 is about 4680.0898495649. The cubic root of 21903241 is about 279.7925376480.

The spelling of 21903241 in words is "twenty-one million, nine hundred three thousand, two hundred forty-one".