21443542 has 4 divisors (see below), whose sum is σ = 32165316. Its totient is φ = 10721770.

The previous prime is 21443519. The next prime is 21443561. The reversal of 21443542 is 24534412.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 5360884 + ... + 5360887.

It is an arithmetic number, because the mean of its divisors is an integer number (8041329).

Almost surely, 2^21443542 is an apocalyptic number.

21443542 is a deficient number, since it is larger than the sum of its proper divisors (10721774).

21443542 is a wasteful number, since it uses less digits than its factorization.

21443542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10721773.

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

The square root of 21443542 is about 4630.7172230660. The cubic root of 21443542 is about 277.8212798121.

Adding to 21443542 its reverse (24534412), we get a palindrome (45977954).

The spelling of 21443542 in words is "twenty-one million, four hundred forty-three thousand, five hundred forty-two".