18416389849 has 45 divisors (see below), whose sum is σ = 22234171659. Its totient is φ = 15242610240.

The previous prime is 18416389841. The next prime is 18416389853. The reversal of 18416389849 is 94898361481.

The square root of 18416389849 is 135707.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 18320976025 + 95413824 = 135355^2 + 9768^2 .

It is not a de Polignac number, because 18416389849 - 2³ = 18416389841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18416389841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 252279277 + ... + 252279349.

Almost surely, 2^18416389849 is an apocalyptic number.

18416389849 is the 135707-th square number.

18416389849 is the 67854-th centered octagonal number.

It is an amenable number.

18416389849 is a deficient number, since it is larger than the sum of its proper divisors (3817781810).

18416389849 is an frugal number, since it uses more digits than its factorization.

18416389849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 97 counting only the distinct ones).

The product of its digits is 11943936, while the sum is 61.

The spelling of 18416389849 in words is "eighteen billion, four hundred sixteen million, three hundred eighty-nine thousand, eight hundred forty-nine".