20512585757 has 2 divisors, whose sum is σ = 20512585758. Its totient is φ = 20512585756.

The previous prime is 20512585739. The next prime is 20512585771. The reversal of 20512585757 is 75758521502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17258339641 + 3254246116 = 131371^2 + 57046^2 .

It is a cyclic number.

It is not a de Polignac number, because 20512585757 - 2²⁶ = 20445476893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20512585957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10256292878 + 10256292879.

It is an arithmetic number, because the mean of its divisors is an integer number (10256292879).

Almost surely, 2^20512585757 is an apocalyptic number.

It is an amenable number.

20512585757 is a deficient number, since it is larger than the sum of its proper divisors (1).

20512585757 is an equidigital number, since it uses as much as digits as its factorization.

20512585757 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980000, while the sum is 47.

The spelling of 20512585757 in words is "twenty billion, five hundred twelve million, five hundred eighty-five thousand, seven hundred fifty-seven".