188457378891 has 4 divisors (see below), whose sum is σ = 251276505192. Its totient is φ = 125638252592.

The previous prime is 188457378803. The next prime is 188457378899. The reversal of 188457378891 is 198873754881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198873754881 = 3 ⋅66291251627.

It is a cyclic number.

It is not a de Polignac number, because 188457378891 - 2⁷ = 188457378763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (188457378899) 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, 31409563146 + ... + 31409563151.

It is an arithmetic number, because the mean of its divisors is an integer number (62819126298).

Almost surely, 2^188457378891 is an apocalyptic number.

188457378891 is a deficient number, since it is larger than the sum of its proper divisors (62819126301).

188457378891 is an equidigital number, since it uses as much as digits as its factorization.

188457378891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62819126300.

The product of its digits is 108380160, while the sum is 69.

The spelling of 188457378891 in words is "one hundred eighty-eight billion, four hundred fifty-seven million, three hundred seventy-eight thousand, eight hundred ninety-one".