221313112021 has 4 divisors (see below), whose sum is σ = 226710992844. Its totient is φ = 215915231200.

The previous prime is 221313112019. The next prime is 221313112043. The reversal of 221313112021 is 120211313122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120211313122 = 2 ⋅60105656561.

It can be written as a sum of positive squares in 2 ways, for example, as 56975303025 + 164337808996 = 238695^2 + 405386^2 .

It is a cyclic number.

It is not a de Polignac number, because 221313112021 - 2¹ = 221313112019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221313112021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221313112721) 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, 2698940350 + ... + 2698940431.

It is an arithmetic number, because the mean of its divisors is an integer number (56677748211).

Almost surely, 2^221313112021 is an apocalyptic number.

It is an amenable number.

221313112021 is a deficient number, since it is larger than the sum of its proper divisors (5397880823).

221313112021 is an equidigital number, since it uses as much as digits as its factorization.

221313112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5397880822.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 221313112021 its reverse (120211313122), we get a palindrome (341524425143).

The spelling of 221313112021 in words is "two hundred twenty-one billion, three hundred thirteen million, one hundred twelve thousand, twenty-one".