1312581 has 4 divisors (see below), whose sum is σ = 1750112. Its totient is φ = 875052.

The previous prime is 1312579. The next prime is 1312583. The reversal of 1312581 is 1852131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1312579) and next prime (1312583).

It is not a de Polignac number, because 1312581 - 2¹ = 1312579 is a prime.

It is a super-2 number, since 2×1312581² = 3445737763122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312583) 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, 218761 + ... + 218766.

It is an arithmetic number, because the mean of its divisors is an integer number (437528).

2^1312581 is an apocalyptic number.

It is an amenable number.

1312581 is a deficient number, since it is larger than the sum of its proper divisors (437531).

1312581 is an equidigital number, since it uses as much as digits as its factorization.

1312581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437530.

The product of its digits is 240, while the sum is 21.

The square root of 1312581 is about 1145.6792744918. The cubic root of 1312581 is about 109.4902307750.

The spelling of 1312581 in words is "one million, three hundred twelve thousand, five hundred eighty-one".