2161870 has 16 divisors (see below), whose sum is σ = 3965760. Its totient is φ = 848224.

The previous prime is 2161853. The next prime is 2161871. The reversal of 2161870 is 781612.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161871) 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, 1510 + ... + 2569.

It is an arithmetic number, because the mean of its divisors is an integer number (247860).

2^2161870 is an apocalyptic number.

2161870 is a deficient number, since it is larger than the sum of its proper divisors (1803890).

2161870 is a wasteful number, since it uses less digits than its factorization.

2161870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4139.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 2161870 is about 1470.3298949556. The cubic root of 2161870 is about 129.3033742797.

The spelling of 2161870 in words is "two million, one hundred sixty-one thousand, eight hundred seventy".