81371780224 has 384 divisors, whose sum is σ = 207964454400. Its totient is φ = 31513337856.

The previous prime is 81371780213. The next prime is 81371780251. The reversal of 81371780224 is 42208717318.

It is a super-3 number, since 3×81371780224³ (a number of 34 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 221721289 + ... + 221721655.

It is an arithmetic number, because the mean of its divisors is an integer number (541574100).

Almost surely, 2^81371780224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81371780224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103982227200).

81371780224 is an abundant number, since it is smaller than the sum of its proper divisors (126592674176).

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

81371780224 is a wasteful number, since it uses less digits than its factorization.

81371780224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500 (or 481 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 43.

The spelling of 81371780224 in words is "eighty-one billion, three hundred seventy-one million, seven hundred eighty thousand, two hundred twenty-four".