221211131 has 4 divisors (see below), whose sum is σ = 221253432. Its totient is φ = 221168832.

The previous prime is 221211127. The next prime is 221211149. The reversal of 221211131 is 131112122.

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

It is a cyclic number.

It is not a de Polignac number, because 221211131 - 2² = 221211127 is a prime.

It is a super-3 number, since 3×221211131³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221210131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11981 + ... + 24206.

It is an arithmetic number, because the mean of its divisors is an integer number (55313358).

Almost surely, 2^221211131 is an apocalyptic number.

221211131 is a deficient number, since it is larger than the sum of its proper divisors (42301).

221211131 is an equidigital number, since it uses as much as digits as its factorization.

221211131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42300.

The product of its digits is 24, while the sum is 14.

The square root of 221211131 is about 14873.1681561125. The cubic root of 221211131 is about 604.7868301651.

Adding to 221211131 its reverse (131112122), we get a palindrome (352323253).

Subtracting from 221211131 its reverse (131112122), we obtain a palindrome (90099009).

The spelling of 221211131 in words is "two hundred twenty-one million, two hundred eleven thousand, one hundred thirty-one".