2161668 has 36 divisors (see below), whose sum is σ = 5334000. Its totient is φ = 681264.

The previous prime is 2161639. The next prime is 2161697. The reversal of 2161668 is 8661612.

It is an interprime number because it is at equal distance from previous prime (2161639) and next prime (2161697).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4083 + ... + 4581.

2^2161668 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 2161668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2667000).

2161668 is an abundant number, since it is smaller than the sum of its proper divisors (3172332).

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

2161668 is a wasteful number, since it uses less digits than its factorization.

2161668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 523 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 2161668 is about 1470.2612012836. The cubic root of 2161668 is about 129.2993468875.

The spelling of 2161668 in words is "two million, one hundred sixty-one thousand, six hundred sixty-eight".