1660989 has 8 divisors (see below), whose sum is σ = 2416032. Its totient is φ = 1006640.

The previous prime is 1660963. The next prime is 1661003. The reversal of 1660989 is 9890661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1660989 - 2⁵ = 1660957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660189) 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 7 ways as a sum of consecutive naturals, for example, 25134 + ... + 25199.

It is an arithmetic number, because the mean of its divisors is an integer number (302004).

2^1660989 is an apocalyptic number.

It is an amenable number.

1660989 is a deficient number, since it is larger than the sum of its proper divisors (755043).

1660989 is a wasteful number, since it uses less digits than its factorization.

1660989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50347.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 1660989 is about 1288.7936219581. The cubic root of 1660989 is about 118.4283246165.

The spelling of 1660989 in words is "one million, six hundred sixty thousand, nine hundred eighty-nine".