2191478 has 4 divisors (see below), whose sum is σ = 3287220. Its totient is φ = 1095738.

The previous prime is 2191477. The next prime is 2191489. The reversal of 2191478 is 8741912.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 547868 + ... + 547871.

It is an arithmetic number, because the mean of its divisors is an integer number (821805).

2^2191478 is an apocalyptic number.

2191478 is a deficient number, since it is larger than the sum of its proper divisors (1095742).

2191478 is a wasteful number, since it uses less digits than its factorization.

2191478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095741.

The product of its digits is 4032, while the sum is 32.

The square root of 2191478 is about 1480.3641443915. The cubic root of 2191478 is about 129.8909934349.

The spelling of 2191478 in words is "two million, one hundred ninety-one thousand, four hundred seventy-eight".