21022744 has 16 divisors (see below), whose sum is σ = 41736600. Its totient is φ = 9892992.

The previous prime is 21022741. The next prime is 21022753. The reversal of 21022744 is 44722012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77154 + ... + 77425.

Almost surely, 2^21022744 is an apocalyptic number.

It is an amenable number.

21022744 is a deficient number, since it is larger than the sum of its proper divisors (20713856).

21022744 is a wasteful number, since it uses less digits than its factorization.

21022744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154602 (or 154598 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21022744 is about 4585.0565972516. The cubic root of 21022744 is about 275.9919832440.

Adding to 21022744 its reverse (44722012), we get a palindrome (65744756).

The spelling of 21022744 in words is "twenty-one million, twenty-two thousand, seven hundred forty-four".