21244669 has 2 divisors, whose sum is σ = 21244670. Its totient is φ = 21244668.

The previous prime is 21244651. The next prime is 21244673. The reversal of 21244669 is 96644212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18164644 + 3080025 = 4262^2 + 1755^2 .

It is a cyclic number.

It is not a de Polignac number, because 21244669 - 2⁵ = 21244637 is a prime.

It is a super-2 number, since 2×21244669² = 902671921839122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21244609) 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, 10622334 + 10622335.

It is an arithmetic number, because the mean of its divisors is an integer number (10622335).

Almost surely, 2^21244669 is an apocalyptic number.

It is an amenable number.

21244669 is a deficient number, since it is larger than the sum of its proper divisors (1).

21244669 is an equidigital number, since it uses as much as digits as its factorization.

21244669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 34.

The square root of 21244669 is about 4609.1939642415. The cubic root of 21244669 is about 276.9597486118.

The spelling of 21244669 in words is "twenty-one million, two hundred forty-four thousand, six hundred sixty-nine".