1998997 has 16 divisors (see below), whose sum is σ = 2685312. Its totient is φ = 1437120.

The previous prime is 1998991. The next prime is 1999007. The reversal of 1998997 is 7998991.

It is a cyclic number.

It is not a de Polignac number, because 1998997 - 2¹¹ = 1996949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998991) 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, 3 + ... + 1999.

It is an arithmetic number, because the mean of its divisors is an integer number (167832).

2^1998997 is an apocalyptic number.

It is an amenable number.

1998997 is a deficient number, since it is larger than the sum of its proper divisors (686315).

1998997 is a wasteful number, since it uses less digits than its factorization.

1998997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028.

The product of its digits is 367416, while the sum is 52.

The square root of 1998997 is about 1413.8589038514. The cubic root of 1998997 is about 125.9710397875.

The spelling of 1998997 in words is "one million, nine hundred ninety-eight thousand, nine hundred ninety-seven".