20933459857 has 2 divisors, whose sum is σ = 20933459858. Its totient is φ = 20933459856.

The previous prime is 20933459839. The next prime is 20933459863. The reversal of 20933459857 is 75895433902.

It is a Cunningham number, because it is equal to 144684²+1.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20933459856 + 1 = 144684^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 20933459857 - 2¹⁵ = 20933427089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20933459798 and 20933459807.

It is not a weakly prime, because it can be changed into another prime (20933409857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10466729928 + 10466729929.

It is an arithmetic number, because the mean of its divisors is an integer number (10466729929).

Almost surely, 2^20933459857 is an apocalyptic number.

It is an amenable number.

20933459857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20933459857 is an equidigital number, since it uses as much as digits as its factorization.

20933459857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8164800, while the sum is 55.

The spelling of 20933459857 in words is "twenty billion, nine hundred thirty-three million, four hundred fifty-nine thousand, eight hundred fifty-seven".