1340689 has 6 divisors (see below), whose sum is σ = 1559634. Its totient is φ = 1149120.

The previous prime is 1340687. The next prime is 1340701. The reversal of 1340689 is 9860431.

1340689 = T₂₀₉ + T₂₁₀ + ... + T₂₅₇.

It can be written as a sum of positive squares in only one way, i.e., 1192464 + 148225 = 1092^2 + 385^2 .

It is not a de Polignac number, because 1340689 - 2¹ = 1340687 is a prime.

It is a Duffinian number.

1340689 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1340689.

It is not an unprimeable number, because it can be changed into a prime (1340681) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13632 + ... + 13729.

It is an arithmetic number, because the mean of its divisors is an integer number (259939).

2^1340689 is an apocalyptic number.

It is an amenable number.

1340689 is a deficient number, since it is larger than the sum of its proper divisors (218945).

1340689 is an equidigital number, since it uses as much as digits as its factorization.

1340689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27375 (or 27368 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 1340689 is about 1157.8812547062. The cubic root of 1340689 is about 110.2662695399.

The spelling of 1340689 in words is "one million, three hundred forty thousand, six hundred eighty-nine".