21232420444 has 12 divisors (see below), whose sum is σ = 37316208384. Its totient is φ = 10570646624.

The previous prime is 21232420421. The next prime is 21232420477. The reversal of 21232420444 is 44402423212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11389852 + ... + 11391715.

It is an arithmetic number, because the mean of its divisors is an integer number (3109684032).

Almost surely, 2^21232420444 is an apocalyptic number.

It is an amenable number.

21232420444 is a deficient number, since it is larger than the sum of its proper divisors (16083787940).

21232420444 is a wasteful number, since it uses less digits than its factorization.

21232420444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22781804 (or 22781802 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 28.

Adding to 21232420444 its reverse (44402423212), we get a palindrome (65634843656).

The spelling of 21232420444 in words is "twenty-one billion, two hundred thirty-two million, four hundred twenty thousand, four hundred forty-four".