1990165 has 4 divisors (see below), whose sum is σ = 2388204. Its totient is φ = 1592128.

The previous prime is 1990159. The next prime is 1990171. The reversal of 1990165 is 5610991.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1990159) and next prime (1990171).

It can be written as a sum of positive squares in 2 ways, for example, as 1085764 + 904401 = 1042^2 + 951^2 .

It is a cyclic number.

It is not a de Polignac number, because 1990165 - 2⁵ = 1990133 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 199012 + ... + 199021.

It is an arithmetic number, because the mean of its divisors is an integer number (597051).

2^1990165 is an apocalyptic number.

It is an amenable number.

1990165 is a deficient number, since it is larger than the sum of its proper divisors (398039).

1990165 is an equidigital number, since it uses as much as digits as its factorization.

1990165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398038.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 1990165 is about 1410.7320794538. The cubic root of 1990165 is about 125.7852434788.

The spelling of 1990165 in words is "one million, nine hundred ninety thousand, one hundred sixty-five".