20111101010221 has 4 divisors (see below), whose sum is σ = 21658108780252. Its totient is φ = 18564093240192.

The previous prime is 20111101010207. The next prime is 20111101010227. The reversal of 20111101010221 is 12201010111102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2419234941321 + 17691866068900 = 1555389^2 + 4206170^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111101010221 - 2²⁵ = 20111067455789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1547007770017 = 20111101010221 / (2 + 0 + 1 + 1 + 1 + 1 + 0 + 1 + 0 + 1 + 0 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111101010227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 773503884996 + ... + 773503885021.

It is an arithmetic number, because the mean of its divisors is an integer number (5414527195063).

Almost surely, 2^{20111101010221} is an apocalyptic number.

It is an amenable number.

20111101010221 is a deficient number, since it is larger than the sum of its proper divisors (1547007770031).

20111101010221 is a wasteful number, since it uses less digits than its factorization.

20111101010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547007770030.

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

Adding to 20111101010221 its reverse (12201010111102), we get a palindrome (32312111121323).

The spelling of 20111101010221 in words is "twenty trillion, one hundred eleven billion, one hundred one million, ten thousand, two hundred twenty-one".