1981199 has 8 divisors (see below), whose sum is σ = 2173392. Its totient is φ = 1791040.

The previous prime is 1981181. The next prime is 1981201. The reversal of 1981199 is 9911891.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1981199 - 2¹⁶ = 1915663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981159) 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, 2177 + ... + 2949.

It is an arithmetic number, because the mean of its divisors is an integer number (271674).

2^1981199 is an apocalyptic number.

1981199 is a deficient number, since it is larger than the sum of its proper divisors (192193).

1981199 is a wasteful number, since it uses less digits than its factorization.

1981199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1017.

The product of its digits is 5832, while the sum is 38.

The square root of 1981199 is about 1407.5507095661. The cubic root of 1981199 is about 125.5960651329.

It can be divided in two parts, 19 and 81199, that added together give a palindrome (81218).

The spelling of 1981199 in words is "one million, nine hundred eighty-one thousand, one hundred ninety-nine".