21442242 has 16 divisors (see below), whose sum is σ = 43090272. Its totient is φ = 7113120.

The previous prime is 21442229. The next prime is 21442243. The reversal of 21442242 is 24224412.

It is not an unprimeable number, because it can be changed into a prime (21442243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7203 + ... + 9734.

It is an arithmetic number, because the mean of its divisors is an integer number (2693142).

Almost surely, 2^21442242 is an apocalyptic number.

21442242 is an abundant number, since it is smaller than the sum of its proper divisors (21648030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21442242 is a wasteful number, since it uses less digits than its factorization.

21442242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17153.

The product of its digits is 1024, while the sum is 21.

The square root of 21442242 is about 4630.5768539136. The cubic root of 21442242 is about 277.8156654572.

Adding to 21442242 its reverse (24224412), we get a palindrome (45666654).

The spelling of 21442242 in words is "twenty-one million, four hundred forty-two thousand, two hundred forty-two".