1988667 has 12 divisors (see below), whose sum is σ = 2909920. Its totient is φ = 1308528.

The previous prime is 1988659. The next prime is 1988669. The reversal of 1988667 is 7668891.

1988667 = 24² + 25² + ... + 181².

It is a happy number.

It is not a de Polignac number, because 1988667 - 2³ = 1988659 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 (1988669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 688 + ... + 2109.

2^1988667 is an apocalyptic number.

1988667 is a deficient number, since it is larger than the sum of its proper divisors (921253).

1988667 is a wasteful number, since it uses less digits than its factorization.

1988667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2882 (or 2879 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 1988667 is about 1410.2010494961. The cubic root of 1988667 is about 125.7536759805.

The spelling of 1988667 in words is "one million, nine hundred eighty-eight thousand, six hundred sixty-seven".