1391889 has 4 divisors (see below), whose sum is σ = 1855856. Its totient is φ = 927924.

The previous prime is 1391861. The next prime is 1391893. The reversal of 1391889 is 9881931.

It is a happy number.

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: 9881931 = 3 ⋅3293977.

It is not a de Polignac number, because 1391889 - 2¹¹ = 1389841 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1391849) 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, 231979 + ... + 231984.

It is an arithmetic number, because the mean of its divisors is an integer number (463964).

2^1391889 is an apocalyptic number.

It is an amenable number.

1391889 is a deficient number, since it is larger than the sum of its proper divisors (463967).

1391889 is an equidigital number, since it uses as much as digits as its factorization.

1391889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463966.

The product of its digits is 15552, while the sum is 39.

The square root of 1391889 is about 1179.7834547068. The cubic root of 1391889 is about 111.6524355023.

The spelling of 1391889 in words is "one million, three hundred ninety-one thousand, eight hundred eighty-nine".