20575956857 has 2 divisors, whose sum is σ = 20575956858. Its totient is φ = 20575956856.

The previous prime is 20575956827. The next prime is 20575956859. The reversal of 20575956857 is 75865957502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15891375721 + 4684581136 = 126061^2 + 68444^2 .

It is a cyclic number.

It is not a de Polignac number, because 20575956857 - 2¹⁶ = 20575891321 is a prime.

It is a super-2 number, since 2×20575956857² (a number of 21 digits) contains 22 as substring.

Together with 20575956859, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20575956796 and 20575956805.

It is not a weakly prime, because it can be changed into another prime (20575956859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10287978428 + 10287978429.

It is an arithmetic number, because the mean of its divisors is an integer number (10287978429).

Almost surely, 2^20575956857 is an apocalyptic number.

It is an amenable number.

20575956857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20575956857 is an equidigital number, since it uses as much as digits as its factorization.

20575956857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460000, while the sum is 59.

The spelling of 20575956857 in words is "twenty billion, five hundred seventy-five million, nine hundred fifty-six thousand, eight hundred fifty-seven".