221312132 has 6 divisors (see below), whose sum is σ = 387296238. Its totient is φ = 110656064.

The previous prime is 221312081. The next prime is 221312149. The reversal of 221312132 is 231213122.

It can be written as a sum of positive squares in only one way, i.e., 183169156 + 38142976 = 13534^2 + 6176^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221312132.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27664013 + ... + 27664020.

It is an arithmetic number, because the mean of its divisors is an integer number (64549373).

Almost surely, 2^221312132 is an apocalyptic number.

It is an amenable number.

221312132 is a deficient number, since it is larger than the sum of its proper divisors (165984106).

221312132 is a wasteful number, since it uses less digits than its factorization.

221312132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55328037 (or 55328035 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 221312132 is about 14876.5631783689. The cubic root of 221312132 is about 604.8788610681.

Adding to 221312132 its reverse (231213122), we get a palindrome (452525254).

The spelling of 221312132 in words is "two hundred twenty-one million, three hundred twelve thousand, one hundred thirty-two".