18903775081 has 3 divisors (see below), whose sum is σ = 18903912573. Its totient is φ = 18903637590.

The previous prime is 18903775021. The next prime is 18903775087. The reversal of 18903775081 is 18057730981.

The square root of 18903775081 is 137491.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 18903775081 - 2¹⁵ = 18903742313 is a prime.

It is a super-2 number, since 2×18903775081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18903775087) 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 2 ways as a sum of consecutive naturals, for example, 68746 + ... + 206236.

It is an arithmetic number, because the mean of its divisors is an integer number (6301304191).

Almost surely, 2^18903775081 is an apocalyptic number.

18903775081 is the 137491-st square number.

18903775081 is the 68746-th centered octagonal number.

It is an amenable number.

18903775081 is a deficient number, since it is larger than the sum of its proper divisors (137492).

18903775081 is an frugal number, since it uses more digits than its factorization.

18903775081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274982 (or 137491 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 49.

Multiplying 18903775081 by its sum of digits (49), we get a square (926284978969 = 962437²).

The spelling of 18903775081 in words is "eighteen billion, nine hundred three million, seven hundred seventy-five thousand, eighty-one".