18919585612225 has 27 divisors (see below), whose sum is σ = 24019749578019. Its totient is φ = 14782945455600.

The previous prime is 18919585612217. The next prime is 18919585612237. The reversal of 18919585612225 is 52221658591981.

The square root of 18919585612225 is 4349665.

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., 6811050820401 + 12108534791824 = 2609799^2 + 3479732^2 .

It is not a de Polignac number, because 18919585612225 - 2³ = 18919585612217 is a prime.

It is a super-2 number, since 2×18919585612225² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 935167860 + ... + 935188090.

Almost surely, 2^{18919585612225} is an apocalyptic number.

18919585612225 is the 4349665-th square number.

18919585612225 is the 2174833-rd centered octagonal number.

It is an amenable number.

18919585612225 is a deficient number, since it is larger than the sum of its proper divisors (5100163965794).

18919585612225 is an frugal number, since it uses more digits than its factorization.

18919585612225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40558 (or 20279 counting only the distinct ones).

The product of its digits is 31104000, while the sum is 64.

The spelling of 18919585612225 in words is "eighteen trillion, nine hundred nineteen billion, five hundred eighty-five million, six hundred twelve thousand, two hundred twenty-five".