221542211 has 4 divisors (see below), whose sum is σ = 241682424. Its totient is φ = 201402000.

The previous prime is 221542183. The next prime is 221542241. The reversal of 221542211 is 112245122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221542211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221542241) 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, 10070090 + ... + 10070111.

It is an arithmetic number, because the mean of its divisors is an integer number (60420606).

Almost surely, 2^221542211 is an apocalyptic number.

221542211 is a deficient number, since it is larger than the sum of its proper divisors (20140213).

221542211 is a wasteful number, since it uses less digits than its factorization.

221542211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20140212.

The product of its digits is 320, while the sum is 20.

The square root of 221542211 is about 14884.2941048610. The cubic root of 221542211 is about 605.0884018080.

Adding to 221542211 its reverse (112245122), we get a palindrome (333787333).

The spelling of 221542211 in words is "two hundred twenty-one million, five hundred forty-two thousand, two hundred eleven".