1981750 has 16 divisors (see below), whose sum is σ = 3710304. Its totient is φ = 792600.

The previous prime is 1981739. The next prime is 1981753. The reversal of 1981750 is 571891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3714 + ... + 4213.

It is an arithmetic number, because the mean of its divisors is an integer number (231894).

2^1981750 is an apocalyptic number.

1981750 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981750 is a deficient number, since it is larger than the sum of its proper divisors (1728554).

1981750 is an equidigital number, since it uses as much as digits as its factorization.

1981750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7944 (or 7934 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 1981750 is about 1407.7464260299. The cubic root of 1981750 is about 125.6077074124.

The spelling of 1981750 in words is "one million, nine hundred eighty-one thousand, seven hundred fifty".