12191451878 has 16 divisors (see below), whose sum is σ = 19295409840. Its totient is φ = 5761173600.

The previous prime is 12191451841. The next prime is 12191451889. The reversal of 12191451878 is 87815419121.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365033 + ... + 397028.

It is an arithmetic number, because the mean of its divisors is an integer number (1205963115).

Almost surely, 2^12191451878 is an apocalyptic number.

12191451878 is a deficient number, since it is larger than the sum of its proper divisors (7103957962).

12191451878 is a wasteful number, since it uses less digits than its factorization.

12191451878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762503.

The product of its digits is 161280, while the sum is 47.

The spelling of 12191451878 in words is "twelve billion, one hundred ninety-one million, four hundred fifty-one thousand, eight hundred seventy-eight".