21124442 has 16 divisors (see below), whose sum is σ = 33488640. Its totient is φ = 9973392.

The previous prime is 21124391. The next prime is 21124459. The reversal of 21124442 is 24442112.

It is a super-2 number, since 2×21124442² = 892484099622728, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 728 + ... + 6540.

It is an arithmetic number, because the mean of its divisors is an integer number (2093040).

Almost surely, 2^21124442 is an apocalyptic number.

21124442 is a deficient number, since it is larger than the sum of its proper divisors (12364198).

21124442 is a wasteful number, since it uses less digits than its factorization.

21124442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5917.

The product of its digits is 512, while the sum is 20.

The square root of 21124442 is about 4596.1333749142. The cubic root of 21124442 is about 276.4363066930.

Adding to 21124442 its reverse (24442112), we get a palindrome (45566554).

The spelling of 21124442 in words is "twenty-one million, one hundred twenty-four thousand, four hundred forty-two".