221421245 has 8 divisors (see below), whose sum is σ = 266867160. Its totient is φ = 176362560.

The previous prime is 221421241. The next prime is 221421257. The reversal of 221421245 is 542124122.

It can be written as a sum of positive squares in 4 ways, for example, as 71554681 + 149866564 = 8459^2 + 12242^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221421245 - 2² = 221421241 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221421245.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221421241) 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, 95546 + ... + 97835.

It is an arithmetic number, because the mean of its divisors is an integer number (33358395).

Almost surely, 2^221421245 is an apocalyptic number.

It is an amenable number.

221421245 is a deficient number, since it is larger than the sum of its proper divisors (45445915).

221421245 is a wasteful number, since it uses less digits than its factorization.

221421245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193615.

The product of its digits is 1280, while the sum is 23.

The square root of 221421245 is about 14880.2300049428. The cubic root of 221421245 is about 604.9782520698.

Adding to 221421245 its reverse (542124122), we get a palindrome (763545367).

The spelling of 221421245 in words is "two hundred twenty-one million, four hundred twenty-one thousand, two hundred forty-five".