81971982530244 has 135 divisors (see below), whose sum is σ = 215111636388957. Its totient is φ = 27219748286016.

The previous prime is 81971982530237. The next prime is 81971982530257. The reversal of 81971982530244 is 44203528917918.

The square root of 81971982530244 is 9053838.

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

81971982530244 is a `hidden beast` number, since 8 + 1 + 9 + 7 + 1 + 98 + 2 + 530 + 2 + 4 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 522945922500 + 81449036607744 = 723150^2 + 9024912^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 51009322489 + ... + 51009324095.

Almost surely, 2^{81971982530244} is an apocalyptic number.

81971982530244 is the 9053838-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81971982530244

81971982530244 is an abundant number, since it is smaller than the sum of its proper divisors (133139653858713).

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

81971982530244 is an frugal number, since it uses more digits than its factorization.

81971982530244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3856 (or 1925 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 63.

The spelling of 81971982530244 in words is "eighty-one trillion, nine hundred seventy-one billion, nine hundred eighty-two million, five hundred thirty thousand, two hundred forty-four".