21844137 has 16 divisors (see below), whose sum is σ = 33612800. Its totient is φ = 12359952.

The previous prime is 21844117. The next prime is 21844139. The reversal of 21844137 is 73144812.

It is not a de Polignac number, because 21844137 - 2¹¹ = 21842089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21844139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2887 + ... + 7212.

It is an arithmetic number, because the mean of its divisors is an integer number (2100800).

Almost surely, 2^21844137 is an apocalyptic number.

It is an amenable number.

21844137 is a deficient number, since it is larger than the sum of its proper divisors (11768663).

21844137 is a wasteful number, since it uses less digits than its factorization.

21844137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10212.

The product of its digits is 5376, while the sum is 30.

The square root of 21844137 is about 4673.7711754000. The cubic root of 21844137 is about 279.5406456272.

Adding to 21844137 its reverse (73144812), we get a palindrome (94988949).

The spelling of 21844137 in words is "twenty-one million, eight hundred forty-four thousand, one hundred thirty-seven".