20391498395887 has 2 divisors, whose sum is σ = 20391498395888. Its totient is φ = 20391498395886.

The previous prime is 20391498395867. The next prime is 20391498395893. The reversal of 20391498395887 is 78859389419302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20391498395887 - 2³⁵ = 20357138657519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20391498395867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10195749197943 + 10195749197944.

It is an arithmetic number, because the mean of its divisors is an integer number (10195749197944).

Almost surely, 2^{20391498395887} is an apocalyptic number.

20391498395887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20391498395887 is an equidigital number, since it uses as much as digits as its factorization.

20391498395887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 940584960, while the sum is 76.

The spelling of 20391498395887 in words is "twenty trillion, three hundred ninety-one billion, four hundred ninety-eight million, three hundred ninety-five thousand, eight hundred eighty-seven".