1665749 has 4 divisors (see below), whose sum is σ = 1753440. Its totient is φ = 1578060.

The previous prime is 1665709. The next prime is 1665757. The reversal of 1665749 is 9475661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1665749 - 2⁸ = 1665493 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43817 + ... + 43854.

It is an arithmetic number, because the mean of its divisors is an integer number (438360).

2^1665749 is an apocalyptic number.

1665749 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1665749 is a deficient number, since it is larger than the sum of its proper divisors (87691).

1665749 is an equidigital number, since it uses as much as digits as its factorization.

1665749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87690.

The product of its digits is 45360, while the sum is 38.

The square root of 1665749 is about 1290.6389890283. The cubic root of 1665749 is about 118.5413458719.

The spelling of 1665749 in words is "one million, six hundred sixty-five thousand, seven hundred forty-nine".