21221111101 has 32 divisors (see below), whose sum is σ = 23474700288. Its totient is φ = 19096197120.

The previous prime is 21221111099. The next prime is 21221111113. The reversal of 21221111101 is 10111112212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21221111101 - 2¹ = 21221111099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221111501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20948271 + ... + 20949283.

It is an arithmetic number, because the mean of its divisors is an integer number (733584384).

Almost surely, 2^21221111101 is an apocalyptic number.

It is an amenable number.

21221111101 is a deficient number, since it is larger than the sum of its proper divisors (2253589187).

21221111101 is a wasteful number, since it uses less digits than its factorization.

21221111101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1501.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21221111101 its reverse (10111112212), we get a palindrome (31332223313).

It can be divided in two parts, 2122111 and 1101, that added together give a palindrome (2123212).

The spelling of 21221111101 in words is "twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, one hundred one".