221111021021021 has 4 divisors (see below), whose sum is σ = 221130694581600. Its totient is φ = 221091347460444.

The previous prime is 221111021020973. The next prime is 221111021021027. The reversal of 221111021021021 is 120120120111122.

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 221111021021021 - 2²⁶ = 221110953912157 is a prime.

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 (221111021021027) 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, 9836763431 + ... + 9836785908.

It is an arithmetic number, because the mean of its divisors is an integer number (55282673645400).

Almost surely, 2^{221111021021021} is an apocalyptic number.

It is an amenable number.

221111021021021 is a deficient number, since it is larger than the sum of its proper divisors (19673560579).

221111021021021 is a wasteful number, since it uses less digits than its factorization.

221111021021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19673560578.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221111021021021 its reverse (120120120111122), we get a palindrome (341231141132143).

The spelling of 221111021021021 in words is "two hundred twenty-one trillion, one hundred eleven billion, twenty-one million, twenty-one thousand, twenty-one".