2161878 has 32 divisors (see below), whose sum is σ = 4561920. Its totient is φ = 682080.

The previous prime is 2161871. The next prime is 2161883. The reversal of 2161878 is 8781612.

It is a happy number.

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

It is a Curzon number.

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 15 ways as a sum of consecutive naturals, for example, 10876 + ... + 11072.

It is an arithmetic number, because the mean of its divisors is an integer number (142560).

2^2161878 is an apocalyptic number.

2161878 is an abundant number, since it is smaller than the sum of its proper divisors (2400042).

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

2161878 is a wasteful number, since it uses less digits than its factorization.

2161878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292.

The product of its digits is 5376, while the sum is 33.

The square root of 2161878 is about 1470.3326154309. The cubic root of 2161878 is about 129.3035337752.

The spelling of 2161878 in words is "two million, one hundred sixty-one thousand, eight hundred seventy-eight".