81438207073344 has 189 divisors, whose sum is σ = 256585298692359. Its totient is φ = 24677522622720.

The previous prime is 81438207073339. The next prime is 81438207073367. The reversal of 81438207073344 is 44337070283418.

The square root of 81438207073344 is 9024312.

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

81438207073344 is a `hidden beast` number, since 8 + 143 + 8 + 20 + 70 + 73 + 344 = 666.

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, 2382401277 + ... + 2382435459.

Almost surely, 2^{81438207073344} is an apocalyptic number.

81438207073344 is the 9024312-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81438207073344

81438207073344 is an abundant number, since it is smaller than the sum of its proper divisors (175147091619015).

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

81438207073344 is an frugal number, since it uses more digits than its factorization.

81438207073344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68406 (or 34199 counting only the distinct ones).

The product of its (nonzero) digits is 10838016, while the sum is 54.

The spelling of 81438207073344 in words is "eighty-one trillion, four hundred thirty-eight billion, two hundred seven million, seventy-three thousand, three hundred forty-four".