21042444406 has 32 divisors (see below), whose sum is σ = 33457950720. Its totient is φ = 9897753600.

The previous prime is 21042444383. The next prime is 21042444407. The reversal of 21042444406 is 60444424012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042444407) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4693686 + ... + 4698166.

It is an arithmetic number, because the mean of its divisors is an integer number (1045560960).

Almost surely, 2^21042444406 is an apocalyptic number.

21042444406 is a deficient number, since it is larger than the sum of its proper divisors (12415506314).

21042444406 is a wasteful number, since it uses less digits than its factorization.

21042444406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5340.

The product of its (nonzero) digits is 24576, while the sum is 31.

Adding to 21042444406 its reverse (60444424012), we get a palindrome (81486868418).

The spelling of 21042444406 in words is "twenty-one billion, forty-two million, four hundred forty-four thousand, four hundred six".