18937888225 has 27 divisors (see below), whose sum is σ = 24961006777. Its totient is φ = 14250308480.

The previous prime is 18937888223. The next prime is 18937888243. The reversal of 18937888225 is 52288873981.

The square root of 18937888225 is 137615.

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

It can be written as a sum of positive squares in 4 ways, for example, as 442976209 + 18494912016 = 21047^2 + 135996^2 .

It is not a de Polignac number, because 18937888225 - 2¹ = 18937888223 is a prime.

It is a super-2 number, since 2×18937888225² (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 (18937888223) 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 26 ways as a sum of consecutive naturals, for example, 11696466 + ... + 11698084.

Almost surely, 2^18937888225 is an apocalyptic number.

18937888225 is the 137615-th square number.

18937888225 is the 68808-th centered octagonal number.

It is an amenable number.

18937888225 is a deficient number, since it is larger than the sum of its proper divisors (6023118552).

18937888225 is an frugal number, since it uses more digits than its factorization.

18937888225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3282 (or 1641 counting only the distinct ones).

The product of its digits is 15482880, while the sum is 61.

The spelling of 18937888225 in words is "eighteen billion, nine hundred thirty-seven million, eight hundred eighty-eight thousand, two hundred twenty-five".