221311223021 has 4 divisors (see below), whose sum is σ = 252927112032. Its totient is φ = 189695334012.

The previous prime is 221311223017. The next prime is 221311223099. The reversal of 221311223021 is 120322113122.

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, and also an emirpimes, since its reverse is a distinct semiprime: 120322113122 = 2 ⋅60161056561.

It is a cyclic number.

It is not a de Polignac number, because 221311223021 - 2² = 221311223017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221311222984 and 221311223002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221311223011) 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, 15807944495 + ... + 15807944508.

It is an arithmetic number, because the mean of its divisors is an integer number (63231778008).

Almost surely, 2^221311223021 is an apocalyptic number.

It is an amenable number.

221311223021 is a deficient number, since it is larger than the sum of its proper divisors (31615889011).

221311223021 is an equidigital number, since it uses as much as digits as its factorization.

221311223021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31615889010.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 221311223021 its reverse (120322113122), we get a palindrome (341633336143).

The spelling of 221311223021 in words is "two hundred twenty-one billion, three hundred eleven million, two hundred twenty-three thousand, twenty-one".