1987173 has 10 divisors (see below), whose sum is σ = 2968614. Its totient is φ = 1324728.

The previous prime is 1987157. The next prime is 1987189. The reversal of 1987173 is 3717891.

It is an interprime number because it is at equal distance from previous prime (1987157) and next prime (1987189).

It can be written as a sum of positive squares in only one way, i.e., 1127844 + 859329 = 1062^2 + 927^2 .

It is not a de Polignac number, because 1987173 - 2⁴ = 1987157 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1987123) 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 9 ways as a sum of consecutive naturals, for example, 12186 + ... + 12347.

2^1987173 is an apocalyptic number.

It is an amenable number.

1987173 is a deficient number, since it is larger than the sum of its proper divisors (981441).

1987173 is an equidigital number, since it uses as much as digits as its factorization.

1987173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24545 (or 24536 counting only the distinct ones).

The product of its digits is 10584, while the sum is 36.

The square root of 1987173 is about 1409.6712382680. The cubic root of 1987173 is about 125.7221769815.

The spelling of 1987173 in words is "one million, nine hundred eighty-seven thousand, one hundred seventy-three".