1656389 has 4 divisors (see below), whose sum is σ = 1893024. Its totient is φ = 1419756.

The previous prime is 1656383. The next prime is 1656427. The reversal of 1656389 is 9836561.

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 1656389 - 2²⁰ = 607813 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656383) 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, 118307 + ... + 118320.

It is an arithmetic number, because the mean of its divisors is an integer number (473256).

2^1656389 is an apocalyptic number.

It is an amenable number.

1656389 is a deficient number, since it is larger than the sum of its proper divisors (236635).

1656389 is an equidigital number, since it uses as much as digits as its factorization.

1656389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236634.

The product of its digits is 38880, while the sum is 38.

The square root of 1656389 is about 1287.0077699843. The cubic root of 1656389 is about 118.3188970464.

The spelling of 1656389 in words is "one million, six hundred fifty-six thousand, three hundred eighty-nine".