221042042121 has 4 divisors (see below), whose sum is σ = 294722722832. Its totient is φ = 147361361412.

The previous prime is 221042042113. The next prime is 221042042203. The reversal of 221042042121 is 121240240122.

221042042121 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 not a de Polignac number, because 221042042121 - 2³ = 221042042113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221042042321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36840340351 + ... + 36840340356.

It is an arithmetic number, because the mean of its divisors is an integer number (73680680708).

Almost surely, 2^221042042121 is an apocalyptic number.

It is an amenable number.

221042042121 is a deficient number, since it is larger than the sum of its proper divisors (73680680711).

221042042121 is an equidigital number, since it uses as much as digits as its factorization.

221042042121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73680680710.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 221042042121 its reverse (121240240122), we get a palindrome (342282282243).

The spelling of 221042042121 in words is "two hundred twenty-one billion, forty-two million, forty-two thousand, one hundred twenty-one".