221542213 has 12 divisors (see below), whose sum is σ = 230038380. Its totient is φ = 213349440.

The previous prime is 221542183. The next prime is 221542241. The reversal of 221542213 is 312245122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 109139809 + 112402404 = 10447^2 + 10602^2 .

It is a de Polignac number, because none of the positive numbers 2^k-221542213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221542613) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 258081 + ... + 258937.

It is an arithmetic number, because the mean of its divisors is an integer number (19169865).

Almost surely, 2^221542213 is an apocalyptic number.

It is an amenable number.

221542213 is a deficient number, since it is larger than the sum of its proper divisors (8496167).

221542213 is an equidigital number, since it uses as much as digits as its factorization.

221542213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1188 (or 1157 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 221542213 is about 14884.2941720459. The cubic root of 221542213 is about 605.0884036288.

Adding to 221542213 its reverse (312245122), we get a palindrome (533787335).

The spelling of 221542213 in words is "two hundred twenty-one million, five hundred forty-two thousand, two hundred thirteen".