21112442 has 16 divisors (see below), whose sum is σ = 34685280. Its totient is φ = 9578352.

The previous prime is 21112433. The next prime is 21112547. The reversal of 21112442 is 24421112.

It is a self number, because there is not a number n which added to its sum of digits gives 21112442.

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, 5348 + ... + 8415.

It is an arithmetic number, because the mean of its divisors is an integer number (2167830).

Almost surely, 2^21112442 is an apocalyptic number.

21112442 is a deficient number, since it is larger than the sum of its proper divisors (13572838).

21112442 is a wasteful number, since it uses less digits than its factorization.

21112442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13837.

The product of its digits is 128, while the sum is 17.

The square root of 21112442 is about 4594.8277443230. The cubic root of 21112442 is about 276.3839524263.

Adding to 21112442 its reverse (24421112), we get a palindrome (45533554).

It can be divided in two parts, 211 and 12442, that multiplied together give a palindrome (2625262).

The spelling of 21112442 in words is "twenty-one million, one hundred twelve thousand, four hundred forty-two".