21774449 has 2 divisors, whose sum is σ = 21774450. Its totient is φ = 21774448.

The previous prime is 21774443. The next prime is 21774451. The reversal of 21774449 is 94447712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12816400 + 8958049 = 3580^2 + 2993^2 .

It is a cyclic number.

It is not a de Polignac number, because 21774449 - 2¹⁶ = 21708913 is a prime.

Together with 21774451, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21774443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887224 + 10887225.

It is an arithmetic number, because the mean of its divisors is an integer number (10887225).

Almost surely, 2^21774449 is an apocalyptic number.

It is an amenable number.

21774449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21774449 is an equidigital number, since it uses as much as digits as its factorization.

21774449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 38.

The square root of 21774449 is about 4666.3099982749. The cubic root of 21774449 is about 279.2430618674.

The spelling of 21774449 in words is "twenty-one million, seven hundred seventy-four thousand, four hundred forty-nine".