21438884 has 6 divisors (see below), whose sum is σ = 37518054. Its totient is φ = 10719440.

The previous prime is 21438881. The next prime is 21438913. The reversal of 21438884 is 48883412.

It can be written as a sum of positive squares in only one way, i.e., 19272100 + 2166784 = 4390^2 + 1472^2 .

It is not an unprimeable number, because it can be changed into a prime (21438881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2679857 + ... + 2679864.

It is an arithmetic number, because the mean of its divisors is an integer number (6253009).

Almost surely, 2^21438884 is an apocalyptic number.

It is an amenable number.

21438884 is a deficient number, since it is larger than the sum of its proper divisors (16079170).

21438884 is a wasteful number, since it uses less digits than its factorization.

21438884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5359725 (or 5359723 counting only the distinct ones).

The product of its digits is 49152, while the sum is 38.

The square root of 21438884 is about 4630.2142499025. The cubic root of 21438884 is about 277.8011620966.

It can be divided in two parts, 21438 and 884, that added together give a palindrome (22322).

The spelling of 21438884 in words is "twenty-one million, four hundred thirty-eight thousand, eight hundred eighty-four".