1381591 has 4 divisors (see below), whose sum is σ = 1390032. Its totient is φ = 1373152.

The previous prime is 1381559. The next prime is 1381609. The reversal of 1381591 is 1951831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1381591 - 2⁵ = 1381559 is a prime.

It is a Duffinian number.

1381591 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3970 + ... + 4303.

It is an arithmetic number, because the mean of its divisors is an integer number (347508).

2^1381591 is an apocalyptic number.

1381591 is a deficient number, since it is larger than the sum of its proper divisors (8441).

1381591 is an equidigital number, since it uses as much as digits as its factorization.

1381591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8440.

The product of its digits is 1080, while the sum is 28.

The square root of 1381591 is about 1175.4109919513. The cubic root of 1381591 is about 111.3763971797.

The spelling of 1381591 in words is "one million, three hundred eighty-one thousand, five hundred ninety-one".