20042261 has 2 divisors, whose sum is σ = 20042262. Its totient is φ = 20042260.

The previous prime is 20042249. The next prime is 20042263. The reversal of 20042261 is 16224002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 1500625 = 4306^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 20042261 - 2¹⁰ = 20041237 is a prime.

It is a Sophie Germain prime.

Together with 20042263, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20042263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10021130 + 10021131.

It is an arithmetic number, because the mean of its divisors is an integer number (10021131).

Almost surely, 2^20042261 is an apocalyptic number.

It is an amenable number.

20042261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20042261 is an equidigital number, since it uses as much as digits as its factorization.

20042261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 20042261 is about 4476.8583850732. The cubic root of 20042261 is about 271.6328171575.

Adding to 20042261 its reverse (16224002), we get a palindrome (36266263).

The spelling of 20042261 in words is "twenty million, forty-two thousand, two hundred sixty-one".