1988687 has 4 divisors (see below), whose sum is σ = 2006400. Its totient is φ = 1970976.

The previous prime is 1988683. The next prime is 1988689. The reversal of 1988687 is 7868891.

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 1988687 - 2² = 1988683 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 (1988683) 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, 8687 + ... + 8912.

It is an arithmetic number, because the mean of its divisors is an integer number (501600).

2^1988687 is an apocalyptic number.

1988687 is a deficient number, since it is larger than the sum of its proper divisors (17713).

1988687 is a wasteful number, since it uses less digits than its factorization.

1988687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17712.

The product of its digits is 193536, while the sum is 47.

The square root of 1988687 is about 1410.2081406658. The cubic root of 1988687 is about 125.7540975468.

The spelling of 1988687 in words is "one million, nine hundred eighty-eight thousand, six hundred eighty-seven".