1391289 has 4 divisors (see below), whose sum is σ = 1855056. Its totient is φ = 927524.

The previous prime is 1391287. The next prime is 1391317. The reversal of 1391289 is 9821931.

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 1391289 - 2¹ = 1391287 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1391281) 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, 231879 + ... + 231884.

It is an arithmetic number, because the mean of its divisors is an integer number (463764).

2^1391289 is an apocalyptic number.

It is an amenable number.

1391289 is a deficient number, since it is larger than the sum of its proper divisors (463767).

1391289 is an equidigital number, since it uses as much as digits as its factorization.

1391289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463766.

The product of its digits is 3888, while the sum is 33.

The square root of 1391289 is about 1179.5291433449. The cubic root of 1391289 is about 111.6363899006.

The spelling of 1391289 in words is "one million, three hundred ninety-one thousand, two hundred eighty-nine".