81423885312 has 1320 divisors, whose sum is σ = 326788320320. Its totient is φ = 19707494400.

The previous prime is 81423885299. The next prime is 81423885353. The reversal of 81423885312 is 21358832418.

81423885312 is a `hidden beast` number, since 8 + 14 + 23 + 88 + 531 + 2 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1334817762 + ... + 1334817822.

Almost surely, 2^81423885312 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 81423885312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163394160160).

81423885312 is an abundant number, since it is smaller than the sum of its proper divisors (245364435008).

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

81423885312 is a wasteful number, since it uses less digits than its factorization.

81423885312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 103 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The spelling of 81423885312 in words is "eighty-one billion, four hundred twenty-three million, eight hundred eighty-five thousand, three hundred twelve".