1340391 has 8 divisors (see below), whose sum is σ = 1924720. Its totient is φ = 824832.

The previous prime is 1340387. The next prime is 1340401. The reversal of 1340391 is 1930431.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1340391 - 2² = 1340387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1340321) 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 7 ways as a sum of consecutive naturals, for example, 17146 + ... + 17223.

It is an arithmetic number, because the mean of its divisors is an integer number (240590).

2^1340391 is an apocalyptic number.

1340391 is a deficient number, since it is larger than the sum of its proper divisors (584329).

1340391 is a wasteful number, since it uses less digits than its factorization.

1340391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34385.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 1340391 is about 1157.7525642381. The cubic root of 1340391 is about 110.2580991680.

It can be divided in two parts, 13 and 40391, that added together give a palindrome (40404).

The spelling of 1340391 in words is "one million, three hundred forty thousand, three hundred ninety-one".