221111220021 has 16 divisors (see below), whose sum is σ = 305581476864. Its totient is φ = 142117843824.

The previous prime is 221111220019. The next prime is 221111220047. The reversal of 221111220021 is 120022111122.

It is not a de Polignac number, because 221111220021 - 2¹ = 221111220019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111220091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11693275 + ... + 11712168.

It is an arithmetic number, because the mean of its divisors is an integer number (19098842304).

Almost surely, 2^221111220021 is an apocalyptic number.

It is an amenable number.

221111220021 is a deficient number, since it is larger than the sum of its proper divisors (84470256843).

221111220021 is a wasteful number, since it uses less digits than its factorization.

221111220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23405560.

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

Adding to 221111220021 its reverse (120022111122), we get a palindrome (341133331143).

The spelling of 221111220021 in words is "two hundred twenty-one billion, one hundred eleven million, two hundred twenty thousand, twenty-one".