2191660 has 12 divisors (see below), whose sum is σ = 4602528. Its totient is φ = 876656.

The previous prime is 2191633. The next prime is 2191687. The reversal of 2191660 is 661912.

It is an interprime number because it is at equal distance from previous prime (2191633) and next prime (2191687).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54772 + ... + 54811.

It is an arithmetic number, because the mean of its divisors is an integer number (383544).

2^2191660 is an apocalyptic number.

2191660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2191660 is an abundant number, since it is smaller than the sum of its proper divisors (2410868).

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

2191660 is a wasteful number, since it uses less digits than its factorization.

2191660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109592 (or 109590 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 2191660 is about 1480.4256144771. The cubic root of 2191660 is about 129.8945891066.

The spelling of 2191660 in words is "two million, one hundred ninety-one thousand, six hundred sixty".