221247427 has 8 divisors (see below), whose sum is σ = 230106800. Its totient is φ = 212556960.

The previous prime is 221247391. The next prime is 221247449. The reversal of 221247427 is 724742122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221247427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221247497) 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, 39552 + ... + 44797.

It is an arithmetic number, because the mean of its divisors is an integer number (28763350).

Almost surely, 2^221247427 is an apocalyptic number.

221247427 is a deficient number, since it is larger than the sum of its proper divisors (8859373).

221247427 is an equidigital number, since it uses as much as digits as its factorization.

221247427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84453.

The product of its digits is 12544, while the sum is 31.

The square root of 221247427 is about 14874.3882899432. The cubic root of 221247427 is about 604.8199058701.

Adding to 221247427 its reverse (724742122), we get a palindrome (945989549).

The spelling of 221247427 in words is "two hundred twenty-one million, two hundred forty-seven thousand, four hundred twenty-seven".