81483415209 has 135 divisors (see below), whose sum is σ = 148774297287. Its totient is φ = 44311440096.

The previous prime is 81483415201. The next prime is 81483415229. The reversal of 81483415209 is 90251438418.

The square root of 81483415209 is 285453.

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

81483415209 is a `hidden beast` number, since 8 + 1 + 4 + 83 + 41 + 520 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 79837328025 + 1646087184 = 282555^2 + 40572^2 .

It is not a de Polignac number, because 81483415209 - 2³ = 81483415201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81483415201) 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, 413621299 + ... + 413621495.

Almost surely, 2^81483415209 is an apocalyptic number.

81483415209 is the 285453-rd square number.

81483415209 is the 142727-th centered octagonal number.

It is an amenable number.

81483415209 is a deficient number, since it is larger than the sum of its proper divisors (67290882078).

81483415209 is an equidigital number, since it uses as much as digits as its factorization.

81483415209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 81483415209 in words is "eighty-one billion, four hundred eighty-three million, four hundred fifteen thousand, two hundred nine".