1661373 has 12 divisors (see below), whose sum is σ = 2742688. Its totient is φ = 949320.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661373 is 3731661.

It is not a de Polignac number, because 1661373 - 2⁸ = 1661117 is a prime.

It is a d-powerful number, because it can be written as 1 + 6³ + 6⁵ + 1 + 3¹⁰ + 7 + 3¹³ .

It is a Duffinian number.

It is a Curzon number.

1661373 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13123 + ... + 13248.

2^1661373 is an apocalyptic number.

It is an amenable number.

1661373 is a deficient number, since it is larger than the sum of its proper divisors (1081315).

1661373 is a wasteful number, since it uses less digits than its factorization.

1661373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26384 (or 26381 counting only the distinct ones).

The product of its digits is 2268, while the sum is 27.

The square root of 1661373 is about 1288.9425898775. The cubic root of 1661373 is about 118.4374502985.

The spelling of 1661373 in words is "one million, six hundred sixty-one thousand, three hundred seventy-three".