19857475891 has 12 divisors (see below), whose sum is σ = 22775807376. Its totient is φ = 17267367920.

The previous prime is 19857475867. The next prime is 19857475901.

19857475891 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 19857475891 - 2⁷ = 19857475763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19857475811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3564856 + ... + 3570421.

It is an arithmetic number, because the mean of its divisors is an integer number (1897983948).

Almost surely, 2^19857475891 is an apocalyptic number.

19857475891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19857475891 is a deficient number, since it is larger than the sum of its proper divisors (2918331485).

19857475891 is a wasteful number, since it uses less digits than its factorization.

19857475891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7135322 (or 7135311 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 64.

The spelling of 19857475891 in words is "nineteen billion, eight hundred fifty-seven million, four hundred seventy-five thousand, eight hundred ninety-one".