221011211021 has 4 divisors (see below), whose sum is σ = 223289677212. Its totient is φ = 218732744832.

The previous prime is 221011210999. The next prime is 221011211053. The reversal of 221011211021 is 120112110122.

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 77378548900 + 143632662121 = 278170^2 + 378989^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011211021 - 2⁶ = 221011210957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221011210987 and 221011211005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221011216021) 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, 1139232950 + ... + 1139233143.

It is an arithmetic number, because the mean of its divisors is an integer number (55822419303).

Almost surely, 2^221011211021 is an apocalyptic number.

It is an amenable number.

221011211021 is a deficient number, since it is larger than the sum of its proper divisors (2278466191).

221011211021 is an equidigital number, since it uses as much as digits as its factorization.

221011211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278466190.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 221011211021 its reverse (120112110122), we get a palindrome (341123321143).

The spelling of 221011211021 in words is "two hundred twenty-one billion, eleven million, two hundred eleven thousand, twenty-one".