1327981 has 4 divisors (see below), whose sum is σ = 1331100. Its totient is φ = 1324864.

The previous prime is 1327973. The next prime is 1327987. The reversal of 1327981 is 1897231.

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 872356 + 455625 = 934^2 + 675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1327981 - 2³ = 1327973 is a prime.

It is a super-2 number, since 2×1327981² = 3527067072722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

1327981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1327987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 796 + ... + 1813.

It is an arithmetic number, because the mean of its divisors is an integer number (332775).

2^1327981 is an apocalyptic number.

It is an amenable number.

1327981 is a deficient number, since it is larger than the sum of its proper divisors (3119).

1327981 is an equidigital number, since it uses as much as digits as its factorization.

1327981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118.

The product of its digits is 3024, while the sum is 31.

The square root of 1327981 is about 1152.3805794962. The cubic root of 1327981 is about 109.9167689954.

The spelling of 1327981 in words is "one million, three hundred twenty-seven thousand, nine hundred eighty-one".