21102244 has 6 divisors (see below), whose sum is σ = 36928934. Its totient is φ = 10551120.

The previous prime is 21102239. The next prime is 21102251. The reversal of 21102244 is 44220112.

It can be written as a sum of positive squares in only one way, i.e., 18662400 + 2439844 = 4320^2 + 1562^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2637777 + ... + 2637784.

Almost surely, 2^21102244 is an apocalyptic number.

It is an amenable number.

21102244 is a deficient number, since it is larger than the sum of its proper divisors (15826690).

21102244 is a wasteful number, since it uses less digits than its factorization.

21102244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5275565 (or 5275563 counting only the distinct ones).

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

The square root of 21102244 is about 4593.7178842415. The cubic root of 21102244 is about 276.3394444297.

Adding to 21102244 its reverse (44220112), we get a palindrome (65322356).

The spelling of 21102244 in words is "twenty-one million, one hundred two thousand, two hundred forty-four".