1667998 has 4 divisors (see below), whose sum is σ = 2502000. Its totient is φ = 833998.

The previous prime is 1667969. The next prime is 1668001. The reversal of 1667998 is 8997661.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416998 + ... + 417001.

It is an arithmetic number, because the mean of its divisors is an integer number (625500).

2^1667998 is an apocalyptic number.

1667998 is a deficient number, since it is larger than the sum of its proper divisors (834002).

1667998 is an equidigital number, since it uses as much as digits as its factorization.

1667998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 834001.

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

The square root of 1667998 is about 1291.5099689898. The cubic root of 1667998 is about 118.5946711516.

The spelling of 1667998 in words is "one million, six hundred sixty-seven thousand, nine hundred ninety-eight".