1398809 has 4 divisors (see below), whose sum is σ = 1401216. Its totient is φ = 1396404.

The previous prime is 1398781. The next prime is 1398841. The reversal of 1398809 is 9088931.

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.

It is a cyclic number.

It is not a de Polignac number, because 1398809 - 2¹² = 1394713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1398209) 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, 272 + ... + 1694.

It is an arithmetic number, because the mean of its divisors is an integer number (350304).

2^1398809 is an apocalyptic number.

It is an amenable number.

1398809 is a deficient number, since it is larger than the sum of its proper divisors (2407).

1398809 is an equidigital number, since it uses as much as digits as its factorization.

1398809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2406.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1398809 is about 1182.7125601768. The cubic root of 1398809 is about 111.8371623861.

The spelling of 1398809 in words is "one million, three hundred ninety-eight thousand, eight hundred nine".