1340457 has 4 divisors (see below), whose sum is σ = 1787280. Its totient is φ = 893636.

The previous prime is 1340447. The next prime is 1340459. The reversal of 1340457 is 7540431.

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: 7540431 = 3 ⋅2513477.

It is a cyclic number.

It is not a de Polignac number, because 1340457 - 2⁴ = 1340441 is a prime.

It is a D-number.

1340457 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1340459) 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, 223407 + ... + 223412.

It is an arithmetic number, because the mean of its divisors is an integer number (446820).

2^1340457 is an apocalyptic number.

It is an amenable number.

1340457 is a deficient number, since it is larger than the sum of its proper divisors (446823).

1340457 is an equidigital number, since it uses as much as digits as its factorization.

1340457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446822.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 1340457 is about 1157.7810673871. The cubic root of 1340457 is about 110.2599088178.

Adding to 1340457 its reverse (7540431), we get a palindrome (8880888).

It can be divided in two parts, 13 and 40457, that added together give a triangular number (40470 = T₂₈₄).

The spelling of 1340457 in words is "one million, three hundred forty thousand, four hundred fifty-seven".