1988911 has 4 divisors (see below), whose sum is σ = 1991952. Its totient is φ = 1985872.

The previous prime is 1988897. The next prime is 1988933. The reversal of 1988911 is 1198891.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1988911 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 (1988941) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 91 + ... + 1996.

It is an arithmetic number, because the mean of its divisors is an integer number (497988).

2^1988911 is an apocalyptic number.

1988911 is a deficient number, since it is larger than the sum of its proper divisors (3041).

1988911 is an equidigital number, since it uses as much as digits as its factorization.

1988911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3040.

The product of its digits is 5184, while the sum is 37.

The square root of 1988911 is about 1410.2875593297. The cubic root of 1988911 is about 125.7588188965.

It can be divided in two parts, 19889 and 11, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 1988911 in words is "one million, nine hundred eighty-eight thousand, nine hundred eleven".