20859293891 has 2 divisors, whose sum is σ = 20859293892. Its totient is φ = 20859293890.

The previous prime is 20859293843. The next prime is 20859293893. The reversal of 20859293891 is 19839295802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20859293891 - 2¹⁸ = 20859031747 is a prime.

It is a super-2 number, since 2×20859293891² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 20859293893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20859293893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10429646945 + 10429646946.

It is an arithmetic number, because the mean of its divisors is an integer number (10429646946).

Almost surely, 2^20859293891 is an apocalyptic number.

20859293891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20859293891 is an equidigital number, since it uses as much as digits as its factorization.

20859293891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2799360, while the sum is 56.

The spelling of 20859293891 in words is "twenty billion, eight hundred fifty-nine million, two hundred ninety-three thousand, eight hundred ninety-one".