21103249 has 2 divisors, whose sum is σ = 21103250. Its totient is φ = 21103248.

The previous prime is 21103241. The next prime is 21103253. The reversal of 21103249 is 94230112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 446224 = 4545^2 + 668^2 .

It is a cyclic number.

It is not a de Polignac number, because 21103249 - 2³ = 21103241 is a prime.

It is equal to p_1336081 and since 21103249 and 1336081 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21103241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551624 + 10551625.

It is an arithmetic number, because the mean of its divisors is an integer number (10551625).

Almost surely, 2^21103249 is an apocalyptic number.

It is an amenable number.

21103249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103249 is an equidigital number, since it uses as much as digits as its factorization.

21103249 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 21103249 is about 4593.8272714590. The cubic root of 21103249 is about 276.3438312734.

The spelling of 21103249 in words is "twenty-one million, one hundred three thousand, two hundred forty-nine".