21221223441 has 16 divisors (see below), whose sum is σ = 31301987328. Its totient is φ = 12680200400.

The previous prime is 21221223421. The next prime is 21221223461. The reversal of 21221223441 is 14432212212.

It is an interprime number because it is at equal distance from previous prime (21221223421) and next prime (21221223461).

It is a cyclic number.

It is not a de Polignac number, because 21221223441 - 2⁷ = 21221223313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221223421) 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, 4526301 + ... + 4530986.

It is an arithmetic number, because the mean of its divisors is an integer number (1956374208).

Almost surely, 2^21221223441 is an apocalyptic number.

It is an amenable number.

21221223441 is a deficient number, since it is larger than the sum of its proper divisors (10080763887).

21221223441 is a wasteful number, since it uses less digits than its factorization.

21221223441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9057372.

The product of its digits is 1536, while the sum is 24.

Adding to 21221223441 its reverse (14432212212), we get a palindrome (35653435653).

The spelling of 21221223441 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty-three thousand, four hundred forty-one".