221500247 has 4 divisors (see below), whose sum is σ = 221638680. Its totient is φ = 221361816.

The previous prime is 221500207. The next prime is 221500261. The reversal of 221500247 is 742005122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221500247 - 2²² = 217305943 is a prime.

It is a super-2 number, since 2×221500247² = 98124718842122018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221500207) 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 3 ways as a sum of consecutive naturals, for example, 66788 + ... + 70025.

It is an arithmetic number, because the mean of its divisors is an integer number (55409670).

Almost surely, 2^221500247 is an apocalyptic number.

221500247 is a deficient number, since it is larger than the sum of its proper divisors (138433).

221500247 is a wasteful number, since it uses less digits than its factorization.

221500247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138432.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 221500247 is about 14882.8843642622. The cubic root of 221500247 is about 605.0501945923.

Adding to 221500247 its reverse (742005122), we get a palindrome (963505369).

The spelling of 221500247 in words is "two hundred twenty-one million, five hundred thousand, two hundred forty-seven".