20144243257 has 2 divisors, whose sum is σ = 20144243258. Its totient is φ = 20144243256.

The previous prime is 20144243191. The next prime is 20144243261. The reversal of 20144243257 is 75234244102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15759287296 + 4384955961 = 125536^2 + 66219^2 .

It is a cyclic number.

It is not a de Polignac number, because 20144243257 - 2³¹ = 17996759609 is a prime.

It is not a weakly prime, because it can be changed into another prime (20144243057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10072121628 + 10072121629.

It is an arithmetic number, because the mean of its divisors is an integer number (10072121629).

Almost surely, 2^20144243257 is an apocalyptic number.

It is an amenable number.

20144243257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20144243257 is an equidigital number, since it uses as much as digits as its factorization.

20144243257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 34.

Adding to 20144243257 its reverse (75234244102), we get a palindrome (95378487359).

The spelling of 20144243257 in words is "twenty billion, one hundred forty-four million, two hundred forty-three thousand, two hundred fifty-seven".