1987659 has 20 divisors (see below), whose sum is σ = 3031776. Its totient is φ = 1297296.

The previous prime is 1987649. The next prime is 1987673. The reversal of 1987659 is 9567891.

It is not a de Polignac number, because 1987659 - 2¹² = 1983563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1987619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4062 + ... + 4524.

2^1987659 is an apocalyptic number.

1987659 is a deficient number, since it is larger than the sum of its proper divisors (1044117).

1987659 is an equidigital number, since it uses as much as digits as its factorization.

1987659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528 (or 519 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 1987659 is about 1409.8436083481. The cubic root of 1987659 is about 125.7324253759.

It can be divided in two parts, 19 and 87659, that added together give a palindrome (87678).

The spelling of 1987659 in words is "one million, nine hundred eighty-seven thousand, six hundred fifty-nine".