1309381 has 4 divisors (see below), whose sum is σ = 1328992. Its totient is φ = 1289772.

The previous prime is 1309369. The next prime is 1309397. The reversal of 1309381 is 1839031.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1839031 = 83 ⋅22157.

It is a cyclic number.

It is not a de Polignac number, because 1309381 - 2⁵ = 1309349 is a prime.

It is a super-2 number, since 2×1309381² = 3428957206322, which contains 22 as substring.

It is a Duffinian number.

1309381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1309351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9705 + ... + 9838.

It is an arithmetic number, because the mean of its divisors is an integer number (332248).

2^1309381 is an apocalyptic number.

It is an amenable number.

1309381 is a deficient number, since it is larger than the sum of its proper divisors (19611).

1309381 is an equidigital number, since it uses as much as digits as its factorization.

1309381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19610.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 1309381 is about 1144.2818708692. The cubic root of 1309381 is about 109.4011813243.

The spelling of 1309381 in words is "one million, three hundred nine thousand, three hundred eighty-one".