21042221432 has 16 divisors (see below), whose sum is σ = 39738010200. Its totient is φ = 10445418720.

The previous prime is 21042221423. The next prime is 21042221443. The reversal of 21042221432 is 23412224012.

It is a junction number, because it is equal to n+sod(n) for n = 21042221398 and 21042221407.

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, 9460319 + ... + 9462542.

Almost surely, 2^21042221432 is an apocalyptic number.

It is an amenable number.

21042221432 is a deficient number, since it is larger than the sum of its proper divisors (18695788768).

21042221432 is a wasteful number, since it uses less digits than its factorization.

21042221432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18923006 (or 18923002 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21042221432 its reverse (23412224012), we get a palindrome (44454445444).

The spelling of 21042221432 in words is "twenty-one billion, forty-two million, two hundred twenty-one thousand, four hundred thirty-two".