1981249 has 4 divisors (see below), whose sum is σ = 1985364. Its totient is φ = 1977136.

The previous prime is 1981247. The next prime is 1981267. The reversal of 1981249 is 9421891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 207025 + 1774224 = 455^2 + 1332^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981249 - 2¹ = 1981247 is a prime.

It is a super-3 number, since 3×1981249³ = 23331273021463143747, which contains 333 as substring.

It is a Duffinian number.

1981249 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1981247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1222 + ... + 2335.

It is an arithmetic number, because the mean of its divisors is an integer number (496341).

2^1981249 is an apocalyptic number.

It is an amenable number.

1981249 is a deficient number, since it is larger than the sum of its proper divisors (4115).

1981249 is an equidigital number, since it uses as much as digits as its factorization.

1981249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4114.

The product of its digits is 5184, while the sum is 34.

The square root of 1981249 is about 1407.5684708035. The cubic root of 1981249 is about 125.5971216902.

The spelling of 1981249 in words is "one million, nine hundred eighty-one thousand, two hundred forty-nine".