221212233 has 48 divisors (see below), whose sum is σ = 361513152. Its totient is φ = 129168000.

The previous prime is 221212223. The next prime is 221212247. The reversal of 221212233 is 332212122.

221212233 is a `hidden beast` number, since 221 + 212 + 233 = 666.

It is not a de Polignac number, because 221212233 - 2⁴ = 221212217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221212223) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 479623 + ... + 480083.

It is an arithmetic number, because the mean of its divisors is an integer number (7531524).

Almost surely, 2^221212233 is an apocalyptic number.

It is an amenable number.

221212233 is a deficient number, since it is larger than the sum of its proper divisors (140300919).

221212233 is a wasteful number, since it uses less digits than its factorization.

221212233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646 (or 643 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 221212233 is about 14873.2052026455. The cubic root of 221212233 is about 604.7878344455.

Adding to 221212233 its reverse (332212122), we get a palindrome (553424355).

It can be divided in two parts, 22121223 and 3, that added together give a triangular number (22121226 = T₆₆₅₁).

The spelling of 221212233 in words is "two hundred twenty-one million, two hundred twelve thousand, two hundred thirty-three".