21444342 has 16 divisors (see below), whose sum is σ = 42939072. Its totient is φ = 7139720.

The previous prime is 21444341. The next prime is 21444347. The reversal of 21444342 is 24344412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444341) 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, 5617 + ... + 8627.

It is an arithmetic number, because the mean of its divisors is an integer number (2683692).

Almost surely, 2^21444342 is an apocalyptic number.

21444342 is an abundant number, since it is smaller than the sum of its proper divisors (21494730).

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

21444342 is a wasteful number, since it uses less digits than its factorization.

21444342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4203.

The product of its digits is 3072, while the sum is 24.

The square root of 21444342 is about 4630.8036019680. The cubic root of 21444342 is about 277.8247346869.

Adding to 21444342 its reverse (24344412), we get a palindrome (45788754).

The spelling of 21444342 in words is "twenty-one million, four hundred forty-four thousand, three hundred forty-two".