1998667 has 16 divisors (see below), whose sum is σ = 2344320. Its totient is φ = 1684800.

The previous prime is 1998643. The next prime is 1998679. The reversal of 1998667 is 7668991.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998667 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1998617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15192 + ... + 15322.

It is an arithmetic number, because the mean of its divisors is an integer number (146520).

2^1998667 is an apocalyptic number.

1998667 is a deficient number, since it is larger than the sum of its proper divisors (345653).

1998667 is a wasteful number, since it uses less digits than its factorization.

1998667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234.

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

The square root of 1998667 is about 1413.7421971491. The cubic root of 1998667 is about 125.9641075225.

The spelling of 1998667 in words is "one million, nine hundred ninety-eight thousand, six hundred sixty-seven".