21244969 has 2 divisors, whose sum is σ = 21244970. Its totient is φ = 21244968.

The previous prime is 21244921. The next prime is 21244991. The reversal of 21244969 is 96944212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17539344 + 3705625 = 4188^2 + 1925^2 .

It is a cyclic number.

It is not a de Polignac number, because 21244969 - 2¹³ = 21236777 is a prime.

It is a super-2 number, since 2×21244969² = 902697415621922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21244999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10622484 + 10622485.

It is an arithmetic number, because the mean of its divisors is an integer number (10622485).

Almost surely, 2^21244969 is an apocalyptic number.

It is an amenable number.

21244969 is a deficient number, since it is larger than the sum of its proper divisors (1).

21244969 is an equidigital number, since it uses as much as digits as its factorization.

21244969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 37.

The square root of 21244969 is about 4609.2265077776. The cubic root of 21244969 is about 276.9610522727.

The spelling of 21244969 in words is "twenty-one million, two hundred forty-four thousand, nine hundred sixty-nine".