21201244 has 24 divisors (see below), whose sum is σ = 39832128. Its totient is φ = 9838080.

The previous prime is 21201209. The next prime is 21201251. The reversal of 21201244 is 44210212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2829 + ... + 7099.

It is an arithmetic number, because the mean of its divisors is an integer number (1659672).

Almost surely, 2^21201244 is an apocalyptic number.

It is an amenable number.

21201244 is a deficient number, since it is larger than the sum of its proper divisors (18630884).

21201244 is a wasteful number, since it uses less digits than its factorization.

21201244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365 (or 4363 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21201244 is about 4604.4808610744. The cubic root of 21201244 is about 276.7709140866.

Adding to 21201244 its reverse (44210212), we get a palindrome (65411456).

It can be divided in two parts, 2120 and 1244, that added together give a square (3364 = 58²).

The spelling of 21201244 in words is "twenty-one million, two hundred one thousand, two hundred forty-four".