220840261 has 2 divisors, whose sum is σ = 220840262. Its totient is φ = 220840260.

The previous prime is 220840259. The next prime is 220840271. The reversal of 220840261 is 162048022.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207187236 + 13653025 = 14394^2 + 3695^2 .

It is a cyclic number.

It is not a de Polignac number, because 220840261 - 2¹ = 220840259 is a prime.

Together with 220840259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220840231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110420130 + 110420131.

It is an arithmetic number, because the mean of its divisors is an integer number (110420131).

Almost surely, 2^220840261 is an apocalyptic number.

It is an amenable number.

220840261 is a deficient number, since it is larger than the sum of its proper divisors (1).

220840261 is an equidigital number, since it uses as much as digits as its factorization.

220840261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 220840261 is about 14860.6951721647. The cubic root of 220840261 is about 604.4486573743.

Adding to 220840261 its reverse (162048022), we get a palindrome (382888283).

The spelling of 220840261 in words is "two hundred twenty million, eight hundred forty thousand, two hundred sixty-one".