221240312 has 32 divisors (see below), whose sum is σ = 458330400. Its totient is φ = 99585024.

The previous prime is 221240309. The next prime is 221240317. The reversal of 221240312 is 213042122.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221240317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32237 + ... + 38492.

It is an arithmetic number, because the mean of its divisors is an integer number (14322825).

Almost surely, 2^221240312 is an apocalyptic number.

It is an amenable number.

221240312 is an abundant number, since it is smaller than the sum of its proper divisors (237090088).

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

221240312 is a wasteful number, since it uses less digits than its factorization.

221240312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70775 (or 70771 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221240312 is about 14874.1491185210. The cubic root of 221240312 is about 604.8134224203.

Adding to 221240312 its reverse (213042122), we get a palindrome (434282434).

It can be divided in two parts, 2212 and 40312, that added together give a palindrome (42524).

The spelling of 221240312 in words is "two hundred twenty-one million, two hundred forty thousand, three hundred twelve".