225191631618 has 54 divisors (see below), whose sum is σ = 501624437769. Its totient is φ = 73010963952.

The previous prime is 225191631607. The next prime is 225191631631. The reversal of 225191631618 is 816136191522.

It is a happy number.

225191631618 is a `hidden beast` number, since 2 + 2 + 5 + 1 + 9 + 1 + 631 + 6 + 1 + 8 = 666.

225191631618 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 181683095049 + 43508536569 = 426243^2 + 208587^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=335553.

It is a super-2 number, since 2×225191631618² (a number of 24 digits) contains 22 as substring.

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, 74491255 + ... + 74494277.

Almost surely, 2^225191631618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 225191631618

225191631618 is an abundant number, since it is smaller than the sum of its proper divisors (276432806151).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

225191631618 is an frugal number, since it uses more digits than its factorization.

225191631618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6128 (or 3065 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The spelling of 225191631618 in words is "two hundred twenty-five billion, one hundred ninety-one million, six hundred thirty-one thousand, six hundred eighteen".