2191947 has 8 divisors (see below), whose sum is σ = 2958144. Its totient is φ = 1443528.

The previous prime is 2191883. The next prime is 2191949. The reversal of 2191947 is 7491912.

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

It is not a de Polignac number, because 2191947 - 2⁶ = 2191883 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2191949) 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, 4153 + ... + 4650.

It is an arithmetic number, because the mean of its divisors is an integer number (369768).

2^2191947 is an apocalyptic number.

2191947 is a deficient number, since it is larger than the sum of its proper divisors (766197).

2191947 is an equidigital number, since it uses as much as digits as its factorization.

2191947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8889.

The product of its digits is 4536, while the sum is 33.

The square root of 2191947 is about 1480.5225428882. The cubic root of 2191947 is about 129.9002587999.

The spelling of 2191947 in words is "two million, one hundred ninety-one thousand, nine hundred forty-seven".