2191015 has 4 divisors (see below), whose sum is σ = 2629224. Its totient is φ = 1752808.

The previous prime is 2191001. The next prime is 2191019. The reversal of 2191015 is 5101912.

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

It is a cyclic number.

It is not a de Polignac number, because 2191015 - 2⁵ = 2190983 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2190983 and 2191001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219097 + ... + 219106.

It is an arithmetic number, because the mean of its divisors is an integer number (657306).

2^2191015 is an apocalyptic number.

2191015 is a deficient number, since it is larger than the sum of its proper divisors (438209).

2191015 is an equidigital number, since it uses as much as digits as its factorization.

2191015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438208.

The product of its (nonzero) digits is 90, while the sum is 19.

The square root of 2191015 is about 1480.2077556884. The cubic root of 2191015 is about 129.8818453066.

Adding to 2191015 its reverse (5101912), we get a palindrome (7292927).

The spelling of 2191015 in words is "two million, one hundred ninety-one thousand, fifteen".