221100112220021 has 4 divisors (see below), whose sum is σ = 221100323528544. Its totient is φ = 221099900911500.

The previous prime is 221100112220011. The next prime is 221100112220083. The reversal of 221100112220021 is 120022211001122.

221100112220021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a de Polignac number, because none of the positive numbers 2^k-221100112220021 is a prime.

It is a super-2 number, since 2×221100112220021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100112220011) 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, 104076905 + ... + 106180046.

It is an arithmetic number, because the mean of its divisors is an integer number (55275080882136).

Almost surely, 2^{221100112220021} is an apocalyptic number.

It is an amenable number.

221100112220021 is a deficient number, since it is larger than the sum of its proper divisors (211308523).

221100112220021 is a wasteful number, since it uses less digits than its factorization.

221100112220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211308522.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221100112220021 its reverse (120022211001122), we get a palindrome (341122323221143).

The spelling of 221100112220021 in words is "two hundred twenty-one trillion, one hundred billion, one hundred twelve million, two hundred twenty thousand, twenty-one".