2191378 has 24 divisors (see below), whose sum is σ = 3898800. Its totient is φ = 920808.

The previous prime is 2191373. The next prime is 2191393. The reversal of 2191378 is 8731912.

It is not an unprimeable number, because it can be changed into a prime (2191373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5593 + ... + 5971.

It is an arithmetic number, because the mean of its divisors is an integer number (162450).

2^2191378 is an apocalyptic number.

2191378 is a deficient number, since it is larger than the sum of its proper divisors (1707422).

2191378 is a wasteful number, since it uses less digits than its factorization.

2191378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454 (or 447 counting only the distinct ones).

The product of its digits is 3024, while the sum is 31.

The square root of 2191378 is about 1480.3303685326. The cubic root of 2191378 is about 129.8890177063.

The spelling of 2191378 in words is "two million, one hundred ninety-one thousand, three hundred seventy-eight".