1667989 has 8 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 1542336.

The previous prime is 1667969. The next prime is 1668001. The reversal of 1667989 is 9897661.

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 1667989 - 2⁵ = 1667957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172 + ... + 1834.

It is an arithmetic number, because the mean of its divisors is an integer number (224640).

2^1667989 is an apocalyptic number.

It is an amenable number.

1667989 is a deficient number, since it is larger than the sum of its proper divisors (129131).

1667989 is a wasteful number, since it uses less digits than its factorization.

1667989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739.

The product of its digits is 163296, while the sum is 46.

The square root of 1667989 is about 1291.5064846914. The cubic root of 1667989 is about 118.5944578512.

The spelling of 1667989 in words is "one million, six hundred sixty-seven thousand, nine hundred eighty-nine".