221543412 has 24 divisors (see below), whose sum is σ = 534760800. Its totient is φ = 71301216.

The previous prime is 221543381. The next prime is 221543417. The reversal of 221543412 is 214345122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221543417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317962 + ... + 318657.

It is an arithmetic number, because the mean of its divisors is an integer number (22281700).

Almost surely, 2^221543412 is an apocalyptic number.

It is an amenable number.

221543412 is an abundant number, since it is smaller than the sum of its proper divisors (313217388).

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

221543412 is a wasteful number, since it uses less digits than its factorization.

221543412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636655 (or 636653 counting only the distinct ones).

The product of its digits is 1920, while the sum is 24.

The square root of 221543412 is about 14884.3344493464. The cubic root of 221543412 is about 605.0894952187.

Adding to 221543412 its reverse (214345122), we get a palindrome (435888534).

The spelling of 221543412 in words is "two hundred twenty-one million, five hundred forty-three thousand, four hundred twelve".