1881891 has 12 divisors (see below), whose sum is σ = 2965560. Its totient is φ = 1140480.

The previous prime is 1881889. The next prime is 1881899. The reversal of 1881891 is 1981881.

It is not a de Polignac number, because 1881891 - 2¹ = 1881889 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881899) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9406 + ... + 9603.

It is an arithmetic number, because the mean of its divisors is an integer number (247130).

2^1881891 is an apocalyptic number.

1881891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1881891 is a deficient number, since it is larger than the sum of its proper divisors (1083669).

1881891 is a wasteful number, since it uses less digits than its factorization.

1881891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19026 (or 19023 counting only the distinct ones).

The product of its digits is 4608, while the sum is 36.

The square root of 1881891 is about 1371.8203235118. The cubic root of 1881891 is about 123.4614827406.

It can be divided in two parts, 1881 and 891, that added together give a palindrome (2772).

The spelling of 1881891 in words is "one million, eight hundred eighty-one thousand, eight hundred ninety-one".