181473444009 has 135 divisors (see below), whose sum is σ = 323636972967. Its totient is φ = 101216887200.

The previous prime is 181473443989. The next prime is 181473444011. The reversal of 181473444009 is 900444374181.

The square root of 181473444009 is 425997.

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., 26845184025 + 154628259984 = 163845^2 + 393228^2 .

It is not a de Polignac number, because 181473444009 - 2⁷ = 181473443881 is a prime.

It is a super-2 number, since 2×181473444009² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (181473544009) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 548257974 + ... + 548258304.

Almost surely, 2^181473444009 is an apocalyptic number.

181473444009 is the 425997-th square number.

181473444009 is the 212999-th centered octagonal number.

It is an amenable number.

181473444009 is a deficient number, since it is larger than the sum of its proper divisors (142163528958).

181473444009 is an equidigital number, since it uses as much as digits as its factorization.

181473444009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722 (or 358 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 181473444009 in words is "one hundred eighty-one billion, four hundred seventy-three million, four hundred forty-four thousand, nine".