221020023121 has 4 divisors (see below), whose sum is σ = 221040410112. Its totient is φ = 220999636132.

The previous prime is 221020023097. The next prime is 221020023139. The reversal of 221020023121 is 121320020122.

It is a happy number.

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 221020023121 - 2³³ = 212430088529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221020023095 and 221020023104.

It is not an unprimeable number, because it can be changed into a prime (221020003121) 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, 10177225 + ... + 10198918.

It is an arithmetic number, because the mean of its divisors is an integer number (55260102528).

Almost surely, 2^221020023121 is an apocalyptic number.

It is an amenable number.

221020023121 is a deficient number, since it is larger than the sum of its proper divisors (20386991).

221020023121 is a wasteful number, since it uses less digits than its factorization.

221020023121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20386990.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 221020023121 its reverse (121320020122), we get a palindrome (342340043243).

The spelling of 221020023121 in words is "two hundred twenty-one billion, twenty million, twenty-three thousand, one hundred twenty-one".