1981140 has 96 divisors (see below), whose sum is σ = 6531840. Its totient is φ = 439296.

The previous prime is 1981099. The next prime is 1981141. The reversal of 1981140 is 411891.

It is a self number, because there is not a number n which added to its sum of digits gives 1981140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981141) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22216 + ... + 22304.

It is an arithmetic number, because the mean of its divisors is an integer number (68040).

2^1981140 is an apocalyptic number.

1981140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3265920).

1981140 is an abundant number, since it is smaller than the sum of its proper divisors (4550700).

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

1981140 is a wasteful number, since it uses less digits than its factorization.

1981140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 1981140 is about 1407.5297510177. The cubic root of 1981140 is about 125.5948183725.

The spelling of 1981140 in words is "one million, nine hundred eighty-one thousand, one hundred forty".