221115043421 has 4 divisors (see below), whose sum is σ = 221937032700. Its totient is φ = 220293054144.

The previous prime is 221115043363. The next prime is 221115043423. The reversal of 221115043421 is 124340511122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8192784196 + 212922259225 = 90514^2 + 461435^2 .

It is a cyclic number.

It is not a de Polignac number, because 221115043421 - 2¹⁴ = 221115027037 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 (221115043423) 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, 410994236 + ... + 410994773.

It is an arithmetic number, because the mean of its divisors is an integer number (55484258175).

Almost surely, 2^221115043421 is an apocalyptic number.

It is an amenable number.

221115043421 is a deficient number, since it is larger than the sum of its proper divisors (821989279).

221115043421 is an equidigital number, since it uses as much as digits as its factorization.

221115043421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821989278.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 221115043421 its reverse (124340511122), we get a palindrome (345455554543).

The spelling of 221115043421 in words is "two hundred twenty-one billion, one hundred fifteen million, forty-three thousand, four hundred twenty-one".