816225425138 has 18 divisors (see below), whose sum is σ = 1292206937679. Its totient is φ = 386621597052.

The previous prime is 816225425131. The next prime is 816225425143. The reversal of 816225425138 is 831524522618.

It can be written as a sum of positive squares in only one way, i.e., 408112712569 + 408112712569 = 638837^2 + 638837^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=638837.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 816225425092 and 816225425101.

It is not an unprimeable number, because it can be changed into a prime (816225425131) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 24258995 + ... + 24292617.

Almost surely, 2^816225425138 is an apocalyptic number.

816225425138 is a deficient number, since it is larger than the sum of its proper divisors (475981512541).

816225425138 is an frugal number, since it uses more digits than its factorization.

816225425138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67286 (or 33644 counting only the distinct ones).

The product of its digits is 921600, while the sum is 47.

The spelling of 816225425138 in words is "eight hundred sixteen billion, two hundred twenty-five million, four hundred twenty-five thousand, one hundred thirty-eight".