21120101011221 has 16 divisors (see below), whose sum is σ = 29821484832768. Its totient is φ = 13249662912000.

The previous prime is 21120101011159. The next prime is 21120101011249. The reversal of 21120101011221 is 12211010102112.

It is a happy number.

It is not a de Polignac number, because 21120101011221 - 2²³ = 21120092622613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21120101011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120101010221) 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, 33515605 + ... + 34139946.

It is an arithmetic number, because the mean of its divisors is an integer number (1863842802048).

Almost surely, 2^{21120101011221} is an apocalyptic number.

It is an amenable number.

21120101011221 is a deficient number, since it is larger than the sum of its proper divisors (8701383821547).

21120101011221 is a wasteful number, since it uses less digits than its factorization.

21120101011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67661692.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21120101011221 its reverse (12211010102112), we get a palindrome (33331111113333).

The spelling of 21120101011221 in words is "twenty-one trillion, one hundred twenty billion, one hundred one million, eleven thousand, two hundred twenty-one".