21244685 has 24 divisors (see below), whose sum is σ = 32355936. Its totient is φ = 13241760.

The previous prime is 21244681. The next prime is 21244693. The reversal of 21244685 is 58644212.

It is not a de Polignac number, because 21244685 - 2² = 21244681 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1247 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (1348164).

Almost surely, 2^21244685 is an apocalyptic number.

It is an amenable number.

21244685 is a deficient number, since it is larger than the sum of its proper divisors (11111251).

21244685 is a wasteful number, since it uses less digits than its factorization.

21244685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7913 (or 7906 counting only the distinct ones).

The product of its digits is 15360, while the sum is 32.

The square root of 21244685 is about 4609.1956999025. The cubic root of 21244685 is about 276.9598181407.

Adding to 21244685 its reverse (58644212), we get a palindrome (79888897).

The spelling of 21244685 in words is "twenty-one million, two hundred forty-four thousand, six hundred eighty-five".