21221321444 has 12 divisors (see below), whose sum is σ = 37240761600. Its totient is φ = 10581103848.

The previous prime is 21221321431. The next prime is 21221321453. The reversal of 21221321444 is 44412312212.

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, 7387604 + ... + 7390475.

It is an arithmetic number, because the mean of its divisors is an integer number (3103396800).

Almost surely, 2^21221321444 is an apocalyptic number.

It is an amenable number.

21221321444 is a deficient number, since it is larger than the sum of its proper divisors (16019440156).

21221321444 is a wasteful number, since it uses less digits than its factorization.

21221321444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14778442 (or 14778440 counting only the distinct ones).

The product of its digits is 3072, while the sum is 26.

Adding to 21221321444 its reverse (44412312212), we get a palindrome (65633633656).

The spelling of 21221321444 in words is "twenty-one billion, two hundred twenty-one million, three hundred twenty-one thousand, four hundred forty-four".