3978191 has 8 divisors (see below), whose sum is σ = 4703520. Its totient is φ = 3292128.

The previous prime is 3978181. The next prime is 3978197. The reversal of 3978191 is 1918793.

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

It is a de Polignac number, because none of the positive numbers 2^k-3978191 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 (3978197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9596 + ... + 10001.

It is an arithmetic number, because the mean of its divisors is an integer number (587940).

Almost surely, 2^3978191 is an apocalyptic number.

3978191 is a deficient number, since it is larger than the sum of its proper divisors (725329).

3978191 is a wasteful number, since it uses less digits than its factorization.

3978191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19633.

The product of its digits is 13608, while the sum is 38.

The square root of 3978191 is about 1994.5402979133. The cubic root of 3978191 is about 158.4510823709.

The spelling of 3978191 in words is "three million, nine hundred seventy-eight thousand, one hundred ninety-one".