221211120021 has 4 divisors (see below), whose sum is σ = 294948160032. Its totient is φ = 147474080012.

The previous prime is 221211120017. The next prime is 221211120029. The reversal of 221211120021 is 120021112122.

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 221211120021 - 2² = 221211120017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221211120029) 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, 36868520001 + ... + 36868520006.

It is an arithmetic number, because the mean of its divisors is an integer number (73737040008).

Almost surely, 2^221211120021 is an apocalyptic number.

It is an amenable number.

221211120021 is a deficient number, since it is larger than the sum of its proper divisors (73737040011).

221211120021 is an equidigital number, since it uses as much as digits as its factorization.

221211120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73737040010.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221211120021 its reverse (120021112122), we get a palindrome (341232232143).

The spelling of 221211120021 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred twenty thousand, twenty-one".