1671891 has 16 divisors (see below), whose sum is σ = 2424576. Its totient is φ = 1018656.

The previous prime is 1671781. The next prime is 1671907. The reversal of 1671891 is 1981761.

It is not a de Polignac number, because 1671891 - 2⁹ = 1671379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1671191) 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, 6226 + ... + 6488.

It is an arithmetic number, because the mean of its divisors is an integer number (151536).

2^1671891 is an apocalyptic number.

1671891 is a deficient number, since it is larger than the sum of its proper divisors (752685).

1671891 is a wasteful number, since it uses less digits than its factorization.

1671891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442.

The product of its digits is 3024, while the sum is 33.

The square root of 1671891 is about 1293.0162411973. The cubic root of 1671891 is about 118.6868635755.

The spelling of 1671891 in words is "one million, six hundred seventy-one thousand, eight hundred ninety-one".