1491789 has 16 divisors (see below), whose sum is σ = 2217600. Its totient is φ = 885696.

The previous prime is 1491773. The next prime is 1491797. The reversal of 1491789 is 9871941.

1491789 = 131² + 132² + ... + 188².

It is a happy number.

It is not a de Polignac number, because 1491789 - 2⁴ = 1491773 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491719) 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 15 ways as a sum of consecutive naturals, for example, 472 + ... + 1790.

It is an arithmetic number, because the mean of its divisors is an integer number (138600).

2^1491789 is an apocalyptic number.

It is an amenable number.

1491789 is a deficient number, since it is larger than the sum of its proper divisors (725811).

1491789 is a wasteful number, since it uses less digits than its factorization.

1491789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364.

The product of its digits is 18144, while the sum is 39.

The square root of 1491789 is about 1221.3881446944. The cubic root of 1491789 is about 114.2621697778.

The spelling of 1491789 in words is "one million, four hundred ninety-one thousand, seven hundred eighty-nine".