13191978 has 8 divisors (see below), whose sum is σ = 26383968. Its totient is φ = 4397324.

The previous prime is 13191977. The next prime is 13191979. The reversal of 13191978 is 87919131.

It is an interprime number because it is at equal distance from previous prime (13191977) and next prime (13191979).

It is a sphenic number, since it is the product of 3 distinct primes.

13191978 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (13191977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1099326 + ... + 1099337.

It is an arithmetic number, because the mean of its divisors is an integer number (3297996).

Almost surely, 2^13191978 is an apocalyptic number.

13191978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13191978 is a wasteful number, since it uses less digits than its factorization.

13191978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2198668.

The product of its digits is 13608, while the sum is 39.

The square root of 13191978 is about 3632.0762657191. The cubic root of 13191978 is about 236.2852650249.

The spelling of 13191978 in words is "thirteen million, one hundred ninety-one thousand, nine hundred seventy-eight".