21944869 has 8 divisors (see below), whose sum is σ = 22809600. Its totient is φ = 21090000.

The previous prime is 21944843. The next prime is 21944887. The reversal of 21944869 is 96844912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21944869 - 2⁵ = 21944837 is a prime.

It is a super-2 number, since 2×21944869² = 963154550854322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21944899) 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 in 7 ways as a sum of consecutive naturals, for example, 2244 + ... + 6994.

It is an arithmetic number, because the mean of its divisors is an integer number (2851200).

Almost surely, 2^21944869 is an apocalyptic number.

It is an amenable number.

21944869 is a deficient number, since it is larger than the sum of its proper divisors (864731).

21944869 is a wasteful number, since it uses less digits than its factorization.

21944869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4931.

The product of its digits is 124416, while the sum is 43.

The square root of 21944869 is about 4684.5350889923. The cubic root of 21944869 is about 279.9696778389.

Adding to 21944869 its sum of digits (43), we get a palindrome (21944912).

The spelling of 21944869 in words is "twenty-one million, nine hundred forty-four thousand, eight hundred sixty-nine".