21101244 has 12 divisors (see below), whose sum is σ = 49236264. Its totient is φ = 7033744.

The previous prime is 21101243. The next prime is 21101251. The reversal of 21101244 is 44210112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 879207 + ... + 879230.

It is an arithmetic number, because the mean of its divisors is an integer number (4103022).

Almost surely, 2^21101244 is an apocalyptic number.

It is an amenable number.

21101244 is an abundant number, since it is smaller than the sum of its proper divisors (28135020).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21101244 is a wasteful number, since it uses less digits than its factorization.

21101244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758444 (or 1758442 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 21101244 is about 4593.6090386536. The cubic root of 21101244 is about 276.3350792730.

Adding to 21101244 its reverse (44210112), we get a palindrome (65311356).

The spelling of 21101244 in words is "twenty-one million, one hundred one thousand, two hundred forty-four".