221011120021 has 4 divisors (see below), whose sum is σ = 221013244044. Its totient is φ = 221008996000.

The previous prime is 221011120007. The next prime is 221011120133. The reversal of 221011120021 is 120021110122.

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 124390236100 + 96620883921 = 352690^2 + 310839^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011120021 - 2¹⁹ = 221010595733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221011119983 and 221011120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221011124021) 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, 897430 + ... + 1116871.

It is an arithmetic number, because the mean of its divisors is an integer number (55253311011).

Almost surely, 2^221011120021 is an apocalyptic number.

It is an amenable number.

221011120021 is a deficient number, since it is larger than the sum of its proper divisors (2124023).

221011120021 is a wasteful number, since it uses less digits than its factorization.

221011120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2124022.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221011120021 its reverse (120021110122), we get a palindrome (341032230143).

The spelling of 221011120021 in words is "two hundred twenty-one billion, eleven million, one hundred twenty thousand, twenty-one".