1985749 has 4 divisors (see below), whose sum is σ = 2003436. Its totient is φ = 1968064.

The previous prime is 1985743. The next prime is 1985759. The reversal of 1985749 is 9475891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9475891 = 643 ⋅14737.

It can be written as a sum of positive squares in 2 ways, for example, as 562500 + 1423249 = 750^2 + 1193^2 .

It is a cyclic number.

It is not a de Polignac number, because 1985749 - 2³ = 1985741 is a prime.

It is a Duffinian number.

1985749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985741) 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, 8674 + ... + 8899.

It is an arithmetic number, because the mean of its divisors is an integer number (500859).

2^1985749 is an apocalyptic number.

It is an amenable number.

1985749 is a deficient number, since it is larger than the sum of its proper divisors (17687).

1985749 is a wasteful number, since it uses less digits than its factorization.

1985749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17686.

The product of its digits is 90720, while the sum is 43.

The square root of 1985749 is about 1409.1660654444. The cubic root of 1985749 is about 125.6921391404.

The spelling of 1985749 in words is "one million, nine hundred eighty-five thousand, seven hundred forty-nine".