21544342 has 4 divisors (see below), whose sum is σ = 32316516. Its totient is φ = 10772170.

The previous prime is 21544331. The next prime is 21544363. The reversal of 21544342 is 24344512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5386084 + ... + 5386087.

It is an arithmetic number, because the mean of its divisors is an integer number (8079129).

Almost surely, 2^21544342 is an apocalyptic number.

21544342 is a deficient number, since it is larger than the sum of its proper divisors (10772174).

21544342 is a wasteful number, since it uses less digits than its factorization.

21544342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10772173.

The product of its digits is 3840, while the sum is 25.

The square root of 21544342 is about 4641.5883057419. The cubic root of 21544342 is about 278.2559191240.

Adding to 21544342 its reverse (24344512), we get a palindrome (45888854).

The spelling of 21544342 in words is "twenty-one million, five hundred forty-four thousand, three hundred forty-two".