221012220021 has 4 divisors (see below), whose sum is σ = 294682960032. Its totient is φ = 147341480012.

The previous prime is 221012219983. The next prime is 221012220061. The reversal of 221012220021 is 120022210122.

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 221012220021 - 2⁹ = 221012219509 is a prime.

It is a super-2 number, since 2×221012220021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012220061) 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, 36835370001 + ... + 36835370006.

It is an arithmetic number, because the mean of its divisors is an integer number (73670740008).

Almost surely, 2^221012220021 is an apocalyptic number.

It is an amenable number.

221012220021 is a deficient number, since it is larger than the sum of its proper divisors (73670740011).

221012220021 is an equidigital number, since it uses as much as digits as its factorization.

221012220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73670740010.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221012220021 its reverse (120022210122), we get a palindrome (341034430143).

The spelling of 221012220021 in words is "two hundred twenty-one billion, twelve million, two hundred twenty thousand, twenty-one".