2191917 has 48 divisors (see below), whose sum is σ = 3881472. Its totient is φ = 1088640.

The previous prime is 2191883. The next prime is 2191949. The reversal of 2191917 is 7191912.

It is not a de Polignac number, because 2191917 - 2¹⁴ = 2175533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191957) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 59223 + ... + 59259.

It is an arithmetic number, because the mean of its divisors is an integer number (80864).

2^2191917 is an apocalyptic number.

2191917 is the 1209-th pentagonal number.

It is an amenable number.

2191917 is a deficient number, since it is larger than the sum of its proper divisors (1689555).

2191917 is a wasteful number, since it uses less digits than its factorization.

2191917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 91 counting only the distinct ones).

The product of its digits is 1134, while the sum is 30.

The square root of 2191917 is about 1480.5124112955. The cubic root of 2191917 is about 129.8996661722.

The spelling of 2191917 in words is "two million, one hundred ninety-one thousand, nine hundred seventeen".