81782310404928 has 224 divisors, whose sum is σ = 249200130187008. Its totient is φ = 23186840371200.

The previous prime is 81782310404903. The next prime is 81782310404929. The reversal of 81782310404928 is 82940401328718.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×81782310404928² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81782310404929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111780076 + ... + 112509332.

It is an arithmetic number, because the mean of its divisors is an integer number (1112500581192).

Almost surely, 2^{81782310404928} 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 81782310404928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124600065093504).

81782310404928 is an abundant number, since it is smaller than the sum of its proper divisors (167417819782080).

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

81782310404928 is a wasteful number, since it uses less digits than its factorization.

81782310404928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729921 (or 729911 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 57.

The spelling of 81782310404928 in words is "eighty-one trillion, seven hundred eighty-two billion, three hundred ten million, four hundred four thousand, nine hundred twenty-eight".