2005720261 has 2 divisors, whose sum is σ = 2005720262. Its totient is φ = 2005720260.

The previous prime is 2005720259. The next prime is 2005720279. The reversal of 2005720261 is 1620275002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1733140161 + 272580100 = 41631^2 + 16510^2 .

It is a cyclic number.

It is not a de Polignac number, because 2005720261 - 2¹ = 2005720259 is a prime.

Together with 2005720259, 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 (2005720291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1002860130 + 1002860131.

It is an arithmetic number, because the mean of its divisors is an integer number (1002860131).

Almost surely, 2^2005720261 is an apocalyptic number.

It is an amenable number.

2005720261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2005720261 is an equidigital number, since it uses as much as digits as its factorization.

2005720261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 2005720261 is about 44785.2683479735. The cubic root of 2005720261 is about 1261.1210860751.

Adding to 2005720261 its reverse (1620275002), we get a palindrome (3625995263).

The spelling of 2005720261 in words is "two billion, five million, seven hundred twenty thousand, two hundred sixty-one".