19380816225 has 27 divisors (see below), whose sum is σ = 34716935929. Its totient is φ = 10335321600.

The previous prime is 19380816211. The next prime is 19380816227. The reversal of 19380816225 is 52261808391.

The square root of 19380816225 is 139215.

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

19380816225 is a `hidden beast` number, since 19 + 3 + 8 + 0 + 8 + 1 + 622 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1801238481 + 17579577744 = 42441^2 + 132588^2 .

It is not a de Polignac number, because 19380816225 - 2⁵ = 19380816193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19380816227) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2083585 + ... + 2092865.

Almost surely, 2^19380816225 is an apocalyptic number.

19380816225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19380816225 is the 139215-th square number.

19380816225 is the 69608-th centered octagonal number.

It is an amenable number.

19380816225 is a deficient number, since it is larger than the sum of its proper divisors (15336119704).

19380816225 is an frugal number, since it uses more digits than its factorization.

19380816225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18578 (or 9289 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 19380816225 in words is "nineteen billion, three hundred eighty million, eight hundred sixteen thousand, two hundred twenty-five".