1399705 has 4 divisors (see below), whose sum is σ = 1679652. Its totient is φ = 1119760.

The previous prime is 1399691. The next prime is 1399709. The reversal of 1399705 is 5079931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5079931 = 613 ⋅8287.

It can be written as a sum of positive squares in 2 ways, for example, as 1098304 + 301401 = 1048^2 + 549^2 .

It is not a de Polignac number, because 1399705 - 2⁷ = 1399577 is a prime.

It is a Duffinian number.

1399705 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399709) 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, 139966 + ... + 139975.

It is an arithmetic number, because the mean of its divisors is an integer number (419913).

2^1399705 is an apocalyptic number.

It is an amenable number.

1399705 is a deficient number, since it is larger than the sum of its proper divisors (279947).

1399705 is an equidigital number, since it uses as much as digits as its factorization.

1399705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279946.

The product of its (nonzero) digits is 8505, while the sum is 34.

The square root of 1399705 is about 1183.0912897997. The cubic root of 1399705 is about 111.8610361981.

The spelling of 1399705 in words is "one million, three hundred ninety-nine thousand, seven hundred five".