221212222 has 16 divisors (see below), whose sum is σ = 413695872. Its totient is φ = 86186520.

The previous prime is 221212219. The next prime is 221212223. The reversal of 221212222 is 222212122.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 221212196 and 221212205.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 718068 + ... + 718375.

It is an arithmetic number, because the mean of its divisors is an integer number (25855992).

Almost surely, 2^221212222 is an apocalyptic number.

221212222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

221212222 is a deficient number, since it is larger than the sum of its proper divisors (192483650).

221212222 is a wasteful number, since it uses less digits than its factorization.

221212222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436463.

The product of its digits is 128, while the sum is 16.

The square root of 221212222 is about 14873.2048328529. The cubic root of 221212222 is about 604.7878244209.

Adding to 221212222 its reverse (222212122), we get a palindrome (443424344).

It can be divided in two parts, 2212122 and 22, that multiplied together give a palindrome (48666684).

The spelling of 221212222 in words is "two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-two".