1398709 has 8 divisors (see below), whose sum is σ = 1595160. Its totient is φ = 1214976.

The previous prime is 1398707. The next prime is 1398721. The reversal of 1398709 is 9078931.

It can be written as a sum of positive squares in 4 ways, for example, as 302500 + 1096209 = 550^2 + 1047^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1398709 - 2¹ = 1398707 is a prime.

It is a Duffinian number.

1398709 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398701) 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, 2944 + ... + 3385.

It is an arithmetic number, because the mean of its divisors is an integer number (199395).

2^1398709 is an apocalyptic number.

It is an amenable number.

1398709 is a deficient number, since it is larger than the sum of its proper divisors (196451).

1398709 is a wasteful number, since it uses less digits than its factorization.

1398709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6359.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 1398709 is about 1182.6702837224. The cubic root of 1398709 is about 111.8344972658.

The spelling of 1398709 in words is "one million, three hundred ninety-eight thousand, seven hundred nine".