20857871873 has 2 divisors, whose sum is σ = 20857871874. Its totient is φ = 20857871872.

The previous prime is 20857871831. The next prime is 20857871891. The reversal of 20857871873 is 37817875802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11478336769 + 9379535104 = 107137^2 + 96848^2 .

It is a cyclic number.

It is not a de Polignac number, because 20857871873 - 2²⁴ = 20841094657 is a prime.

It is not a weakly prime, because it can be changed into another prime (20857871893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10428935936 + 10428935937.

It is an arithmetic number, because the mean of its divisors is an integer number (10428935937).

Almost surely, 2^20857871873 is an apocalyptic number.

It is an amenable number.

20857871873 is a deficient number, since it is larger than the sum of its proper divisors (1).

20857871873 is an equidigital number, since it uses as much as digits as its factorization.

20857871873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5268480, while the sum is 56.

The spelling of 20857871873 in words is "twenty billion, eight hundred fifty-seven million, eight hundred seventy-one thousand, eight hundred seventy-three".