1987559 has 4 divisors (see below), whose sum is σ = 2271504. Its totient is φ = 1703616.

The previous prime is 1987549. The next prime is 1987577. The reversal of 1987559 is 9557891.

It is a happy number.

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 1987559 - 2⁴ = 1987543 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 (1987519) 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, 141962 + ... + 141975.

It is an arithmetic number, because the mean of its divisors is an integer number (567876).

2^1987559 is an apocalyptic number.

1987559 is a deficient number, since it is larger than the sum of its proper divisors (283945).

1987559 is an equidigital number, since it uses as much as digits as its factorization.

1987559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283944.

The product of its digits is 113400, while the sum is 44.

The square root of 1987559 is about 1409.8081429755. The cubic root of 1987559 is about 125.7303167893.

It can be divided in two parts, 19 and 87559, that added together give a palindrome (87578).

The spelling of 1987559 in words is "one million, nine hundred eighty-seven thousand, five hundred fifty-nine".