2191617 has 24 divisors (see below), whose sum is σ = 3407040. Its totient is φ = 1406160.

The previous prime is 2191583. The next prime is 2191619. The reversal of 2191617 is 7161912.

It is not a de Polignac number, because 2191617 - 2⁷ = 2191489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2191619) 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 23 ways as a sum of consecutive naturals, for example, 6892 + ... + 7202.

It is an arithmetic number, because the mean of its divisors is an integer number (141960).

2^2191617 is an apocalyptic number.

2191617 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

2191617 is a deficient number, since it is larger than the sum of its proper divisors (1215423).

2191617 is an equidigital number, since it uses as much as digits as its factorization.

2191617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 343 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 2191617 is about 1480.4110915553. The cubic root of 2191617 is about 129.8937395977.

The spelling of 2191617 in words is "two million, one hundred ninety-one thousand, six hundred seventeen".