1981329 has 8 divisors (see below), whose sum is σ = 3019200. Its totient is φ = 1132176.

The previous prime is 1981297. The next prime is 1981337. The reversal of 1981329 is 9231891.

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

It is not a de Polignac number, because 1981329 - 2⁵ = 1981297 is a prime.

It is a super-3 number, since 3×1981329³ = 23334099385856622867, which contains 333 as substring.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1981329.

It is not an unprimeable number, because it can be changed into a prime (1981349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47154 + ... + 47195.

It is an arithmetic number, because the mean of its divisors is an integer number (377400).

2^1981329 is an apocalyptic number.

It is an amenable number.

1981329 is a deficient number, since it is larger than the sum of its proper divisors (1037871).

1981329 is an equidigital number, since it uses as much as digits as its factorization.

1981329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94359.

The product of its digits is 3888, while the sum is 33.

The square root of 1981329 is about 1407.5968883171. The cubic root of 1981329 is about 125.5988121448.

The spelling of 1981329 in words is "one million, nine hundred eighty-one thousand, three hundred twenty-nine".