2163891 has 8 divisors (see below), whose sum is σ = 3037120. Its totient is φ = 1366632.

The previous prime is 2163883. The next prime is 2163911. The reversal of 2163891 is 1983612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2163891 - 2³ = 2163883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2163851) 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, 18925 + ... + 19038.

It is an arithmetic number, because the mean of its divisors is an integer number (379640).

2^2163891 is an apocalyptic number.

2163891 is a deficient number, since it is larger than the sum of its proper divisors (873229).

2163891 is a wasteful number, since it uses less digits than its factorization.

2163891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37985.

The product of its digits is 2592, while the sum is 30.

The square root of 2163891 is about 1471.0169951432. The cubic root of 2163891 is about 129.3436543351.

It can be divided in two parts, 216 and 3891, that multiplied together give a triangular number (840456 = T₁₂₉₆).

The spelling of 2163891 in words is "two million, one hundred sixty-three thousand, eight hundred ninety-one".