20505342131 has 2 divisors, whose sum is σ = 20505342132. Its totient is φ = 20505342130.

The previous prime is 20505342079. The next prime is 20505342157. The reversal of 20505342131 is 13124350502.

It is a happy number.

It is an a-pointer prime, because the next prime (20505342157) can be obtained adding 20505342131 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20505342131 - 2¹⁰ = 20505341107 is a prime.

It is a super-2 number, since 2×20505342131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20505342131.

It is not a weakly prime, because it can be changed into another prime (20505345131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10252671065 + 10252671066.

It is an arithmetic number, because the mean of its divisors is an integer number (10252671066).

Almost surely, 2^20505342131 is an apocalyptic number.

20505342131 is a deficient number, since it is larger than the sum of its proper divisors (1).

20505342131 is an equidigital number, since it uses as much as digits as its factorization.

20505342131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 20505342131 its reverse (13124350502), we get a palindrome (33629692633).

The spelling of 20505342131 in words is "twenty billion, five hundred five million, three hundred forty-two thousand, one hundred thirty-one".