1649675789 has 4 divisors (see below), whose sum is σ = 1650381024. Its totient is φ = 1648970556.

The previous prime is 1649675749. The next prime is 1649675791. The reversal of 1649675789 is 9875769461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9875769461 = 3433 ⋅2876717.

It is a cyclic number.

It is not a de Polignac number, because 1649675789 - 2¹⁶ = 1649610253 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 (1649675719) 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, 349097 + ... + 353790.

It is an arithmetic number, because the mean of its divisors is an integer number (412595256).

Almost surely, 2^1649675789 is an apocalyptic number.

It is an amenable number.

1649675789 is a deficient number, since it is larger than the sum of its proper divisors (705235).

1649675789 is an equidigital number, since it uses as much as digits as its factorization.

1649675789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705234.

The product of its digits is 22861440, while the sum is 62.

The square root of 1649675789 is about 40616.2010655847. The cubic root of 1649675789 is about 1181.5883496332.

The spelling of 1649675789 in words is "one billion, six hundred forty-nine million, six hundred seventy-five thousand, seven hundred eighty-nine".