220231909 has 2 divisors, whose sum is σ = 220231910. Its totient is φ = 220231908.

The previous prime is 220231871. The next prime is 220231919. The reversal of 220231909 is 909132022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219691684 + 540225 = 14822^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 220231909 - 2²¹ = 218134757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220231919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110115954 + 110115955.

It is an arithmetic number, because the mean of its divisors is an integer number (110115955).

Almost surely, 2^220231909 is an apocalyptic number.

It is an amenable number.

220231909 is a deficient number, since it is larger than the sum of its proper divisors (1).

220231909 is an equidigital number, since it uses as much as digits as its factorization.

220231909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 220231909 is about 14840.2125658631. The cubic root of 220231909 is about 603.8931189986.

It can be divided in two parts, 22023 and 1909, that added together give a palindrome (23932).

The spelling of 220231909 in words is "two hundred twenty million, two hundred thirty-one thousand, nine hundred nine".