21101120221 has 4 divisors (see below), whose sum is σ = 21102195744. Its totient is φ = 21100044700.

The previous prime is 21101120203. The next prime is 21101120233. The reversal of 21101120221 is 12202110112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21101120221 - 2⁹ = 21101119709 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 (21101120251) 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, 507775 + ... + 547756.

It is an arithmetic number, because the mean of its divisors is an integer number (5275548936).

Almost surely, 2^21101120221 is an apocalyptic number.

It is an amenable number.

21101120221 is a deficient number, since it is larger than the sum of its proper divisors (1075523).

21101120221 is a wasteful number, since it uses less digits than its factorization.

21101120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075522.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21101120221 its reverse (12202110112), we get a palindrome (33303230333).

The spelling of 21101120221 in words is "twenty-one billion, one hundred one million, one hundred twenty thousand, two hundred twenty-one".