1320581 has 4 divisors (see below), whose sum is σ = 1323564. Its totient is φ = 1317600.

The previous prime is 1320541. The next prime is 1320607. The reversal of 1320581 is 1850231.

1320581 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1850231 = 223 ⋅8297.

It can be written as a sum of positive squares in 2 ways, for example, as 302500 + 1018081 = 550^2 + 1009^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320581 is a prime.

It is a super-2 number, since 2×1320581² = 3487868355122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320541) 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, 680 + ... + 1761.

It is an arithmetic number, because the mean of its divisors is an integer number (330891).

2^1320581 is an apocalyptic number.

It is an amenable number.

1320581 is a deficient number, since it is larger than the sum of its proper divisors (2983).

1320581 is an equidigital number, since it uses as much as digits as its factorization.

1320581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2982.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1320581 is about 1149.1653492862. The cubic root of 1320581 is about 109.7122229940.

The spelling of 1320581 in words is "one million, three hundred twenty thousand, five hundred eighty-one".