1398689 has 4 divisors (see below), whose sum is σ = 1443840. Its totient is φ = 1353540.

The previous prime is 1398667. The next prime is 1398701. The reversal of 1398689 is 9868931.

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: 9868931 = 107 ⋅92233.

It is a cyclic number.

It is not a de Polignac number, because 1398689 - 2¹⁶ = 1333153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1398619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22529 + ... + 22590.

It is an arithmetic number, because the mean of its divisors is an integer number (360960).

2^1398689 is an apocalyptic number.

It is an amenable number.

1398689 is a deficient number, since it is larger than the sum of its proper divisors (45151).

1398689 is an equidigital number, since it uses as much as digits as its factorization.

1398689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45150.

The product of its digits is 93312, while the sum is 44.

The square root of 1398689 is about 1182.6618282502. The cubic root of 1398689 is about 111.8339642265.

The spelling of 1398689 in words is "one million, three hundred ninety-eight thousand, six hundred eighty-nine".