221212422 has 48 divisors (see below), whose sum is σ = 486907200. Its totient is φ = 72576000.

The previous prime is 221212361. The next prime is 221212423. The reversal of 221212422 is 224212122.

221212422 is a `hidden beast` number, since 221 + 21 + 2 + 422 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 221212395 and 221212404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 492454 + ... + 492902.

It is an arithmetic number, because the mean of its divisors is an integer number (10143900).

Almost surely, 2^221212422 is an apocalyptic number.

221212422 is an abundant number, since it is smaller than the sum of its proper divisors (265694778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221212422 is a wasteful number, since it uses less digits than its factorization.

221212422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829 (or 826 counting only the distinct ones).

The product of its digits is 256, while the sum is 18.

The square root of 221212422 is about 14873.2115563519. The cubic root of 221212422 is about 604.7880066856.

Adding to 221212422 its reverse (224212122), we get a palindrome (445424544).

The spelling of 221212422 in words is "two hundred twenty-one million, two hundred twelve thousand, four hundred twenty-two".