20791377889 has 2 divisors, whose sum is σ = 20791377890. Its totient is φ = 20791377888.

The previous prime is 20791377883. The next prime is 20791377911. The reversal of 20791377889 is 98877319702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11840704225 + 8950673664 = 108815^2 + 94608^2 .

It is a cyclic number.

It is not a de Polignac number, because 20791377889 - 2³ = 20791377881 is a prime.

It is not a weakly prime, because it can be changed into another prime (20791377881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10395688944 + 10395688945.

It is an arithmetic number, because the mean of its divisors is an integer number (10395688945).

Almost surely, 2^20791377889 is an apocalyptic number.

It is an amenable number.

20791377889 is a deficient number, since it is larger than the sum of its proper divisors (1).

20791377889 is an equidigital number, since it uses as much as digits as its factorization.

20791377889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10668672, while the sum is 61.

The spelling of 20791377889 in words is "twenty billion, seven hundred ninety-one million, three hundred seventy-seven thousand, eight hundred eighty-nine".