1641684889 has 4 divisors (see below), whose sum is σ = 1767968356. Its totient is φ = 1515401424.

The previous prime is 1641684871. The next prime is 1641684923. The reversal of 1641684889 is 9884861461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9884861461 = 64157 ⋅154073.

It can be written as a sum of positive squares in 2 ways, for example, as 249798025 + 1391886864 = 15805^2 + 37308^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641684889 - 2⁹ = 1641684377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1641684829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63141714 + ... + 63141739.

It is an arithmetic number, because the mean of its divisors is an integer number (441992089).

Almost surely, 2^1641684889 is an apocalyptic number.

It is an amenable number.

1641684889 is a deficient number, since it is larger than the sum of its proper divisors (126283467).

1641684889 is a wasteful number, since it uses less digits than its factorization.

1641684889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126283466.

The product of its digits is 2654208, while the sum is 55.

The square root of 1641684889 is about 40517.7108065103. The cubic root of 1641684889 is about 1179.6774204419.

The spelling of 1641684889 in words is "one billion, six hundred forty-one million, six hundred eighty-four thousand, eight hundred eighty-nine".