2191281 has 8 divisors (see below), whose sum is σ = 2984064. Its totient is φ = 1429680.

The previous prime is 2191261. The next prime is 2191291. The reversal of 2191281 is 1821912.

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

It is a de Polignac number, because none of the positive numbers 2^k-2191281 is a prime.

It is a super-4 number, since 4×2191281⁴ (a number of 26 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

2191281 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2191261) 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, 7630 + ... + 7911.

It is an arithmetic number, because the mean of its divisors is an integer number (373008).

2^2191281 is an apocalyptic number.

It is an amenable number.

2191281 is a deficient number, since it is larger than the sum of its proper divisors (792783).

2191281 is a wasteful number, since it uses less digits than its factorization.

2191281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15591.

The product of its digits is 288, while the sum is 24.

The square root of 2191281 is about 1480.2976052132. The cubic root of 2191281 is about 129.8871011922.

The spelling of 2191281 in words is "two million, one hundred ninety-one thousand, two hundred eighty-one".