221040247 has 2 divisors, whose sum is σ = 221040248. Its totient is φ = 221040246.

The previous prime is 221040241. The next prime is 221040251. The reversal of 221040247 is 742040122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221040247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221040241) 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 as a sum of consecutive naturals, namely, 110520123 + 110520124.

It is an arithmetic number, because the mean of its divisors is an integer number (110520124).

Almost surely, 2^221040247 is an apocalyptic number.

221040247 is a deficient number, since it is larger than the sum of its proper divisors (1).

221040247 is an equidigital number, since it uses as much as digits as its factorization.

221040247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 221040247 is about 14867.4223387916. The cubic root of 221040247 is about 604.6310588957.

Adding to 221040247 its reverse (742040122), we get a palindrome (963080369).

The spelling of 221040247 in words is "two hundred twenty-one million, forty thousand, two hundred forty-seven".