19878558893 has 4 divisors (see below), whose sum is σ = 20215483680. Its totient is φ = 19541634108.

The previous prime is 19878558857. The next prime is 19878558899. The reversal of 19878558893 is 39885587891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39885587891 = 84809 ⋅470299.

It is a cyclic number.

It is not a de Polignac number, because 19878558893 - 2⁶ = 19878558829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19878558899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168462305 + ... + 168462422.

It is an arithmetic number, because the mean of its divisors is an integer number (5053870920).

Almost surely, 2^19878558893 is an apocalyptic number.

It is an amenable number.

19878558893 is a deficient number, since it is larger than the sum of its proper divisors (336924787).

19878558893 is an equidigital number, since it uses as much as digits as its factorization.

19878558893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336924786.

The product of its digits is 174182400, while the sum is 71.

The spelling of 19878558893 in words is "nineteen billion, eight hundred seventy-eight million, five hundred fifty-eight thousand, eight hundred ninety-three".