1981143 has 12 divisors (see below), whose sum is σ = 2876328. Its totient is φ = 1314000.

The previous prime is 1981141. The next prime is 1981153. The reversal of 1981143 is 3411891.

It is not a de Polignac number, because 1981143 - 2¹ = 1981141 is a prime.

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 11 ways as a sum of consecutive naturals, for example, 1821 + ... + 2697.

It is an arithmetic number, because the mean of its divisors is an integer number (239694).

2^1981143 is an apocalyptic number.

1981143 is a deficient number, since it is larger than the sum of its proper divisors (895185).

1981143 is a wasteful number, since it uses less digits than its factorization.

1981143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134 (or 1131 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 1981143 is about 1407.5308167141. The cubic root of 1981143 is about 125.5948817677.

The spelling of 1981143 in words is "one million, nine hundred eighty-one thousand, one hundred forty-three".