1645849789 has 8 divisors (see below), whose sum is σ = 1709917560. Its totient is φ = 1582269696.

The previous prime is 1645849783. The next prime is 1645849817. The reversal of 1645849789 is 9879485461.

It can be written as a sum of positive squares in 4 ways, for example, as 24176889 + 1621672900 = 4917^2 + 40270^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1645849789 - 2⁷ = 1645849661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645849783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115032 + ... + 128545.

It is an arithmetic number, because the mean of its divisors is an integer number (213739695).

Almost surely, 2^1645849789 is an apocalyptic number.

It is an amenable number.

1645849789 is a deficient number, since it is larger than the sum of its proper divisors (64067771).

1645849789 is a wasteful number, since it uses less digits than its factorization.

1645849789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243839.

The product of its digits is 17418240, while the sum is 61.

The square root of 1645849789 is about 40569.0742931115. The cubic root of 1645849789 is about 1180.6741788047.

The spelling of 1645849789 in words is "one billion, six hundred forty-five million, eight hundred forty-nine thousand, seven hundred eighty-nine".