1987165 has 4 divisors (see below), whose sum is σ = 2384604. Its totient is φ = 1589728.

The previous prime is 1987157. The next prime is 1987189. The reversal of 1987165 is 5617891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5617891 = 643 ⋅8737.

It can be written as a sum of positive squares in 2 ways, for example, as 481636 + 1505529 = 694^2 + 1227^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987165 - 2³ = 1987157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198712 + ... + 198721.

It is an arithmetic number, because the mean of its divisors is an integer number (596151).

2^1987165 is an apocalyptic number.

It is an amenable number.

1987165 is a deficient number, since it is larger than the sum of its proper divisors (397439).

1987165 is an equidigital number, since it uses as much as digits as its factorization.

1987165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397438.

The product of its digits is 15120, while the sum is 37.

The square root of 1987165 is about 1409.6684007241. The cubic root of 1987165 is about 125.7220082697.

The spelling of 1987165 in words is "one million, nine hundred eighty-seven thousand, one hundred sixty-five".