1998511 has 4 divisors (see below), whose sum is σ = 2045032. Its totient is φ = 1951992.

The previous prime is 1998497. The next prime is 1998517. The reversal of 1998511 is 1158991.

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

It is a cyclic number.

It is not a de Polignac number, because 1998511 - 2⁹ = 1997999 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23196 + ... + 23281.

It is an arithmetic number, because the mean of its divisors is an integer number (511258).

2^1998511 is an apocalyptic number.

1998511 is a deficient number, since it is larger than the sum of its proper divisors (46521).

1998511 is an equidigital number, since it uses as much as digits as its factorization.

1998511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46520.

The product of its digits is 3240, while the sum is 34.

The square root of 1998511 is about 1413.6870233542. The cubic root of 1998511 is about 125.9608301861.

The spelling of 1998511 in words is "one million, nine hundred ninety-eight thousand, five hundred eleven".