2191656 has 32 divisors (see below), whose sum is σ = 5585760. Its totient is φ = 716352.

The previous prime is 2191633. The next prime is 2191687. The reversal of 2191656 is 6561912.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411 + ... + 2133.

It is an arithmetic number, because the mean of its divisors is an integer number (174555).

2^2191656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2191656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2792880).

2191656 is an abundant number, since it is smaller than the sum of its proper divisors (3394104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2191656 is a wasteful number, since it uses less digits than its factorization.

2191656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1785 (or 1781 counting only the distinct ones).

The product of its digits is 3240, while the sum is 30.

The square root of 2191656 is about 1480.4242635137. The cubic root of 2191656 is about 129.8945100830.

The spelling of 2191656 in words is "two million, one hundred ninety-one thousand, six hundred fifty-six".