18723269889 has 27 divisors (see below), whose sum is σ = 28739881443. Its totient is φ = 11743555392.

The previous prime is 18723269869. The next prime is 18723269893. The reversal of 18723269889 is 98896232781.

The square root of 18723269889 is 136833.

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

It can be written as a sum of positive squares in only one way, i.e., 14576940225 + 4146329664 = 120735^2 + 64392^2 .

It is not a de Polignac number, because 18723269889 - 2²¹ = 18721172737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18723269849) 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 26 ways as a sum of consecutive naturals, for example, 6977142 + ... + 6979824.

Almost surely, 2^18723269889 is an apocalyptic number.

18723269889 is the 136833-rd square number.

18723269889 is the 68417-th centered octagonal number.

It is an amenable number.

18723269889 is a deficient number, since it is larger than the sum of its proper divisors (10016611554).

18723269889 is an frugal number, since it uses more digits than its factorization.

18723269889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5406 (or 2703 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 63.

The spelling of 18723269889 in words is "eighteen billion, seven hundred twenty-three million, two hundred sixty-nine thousand, eight hundred eighty-nine".