81213694848 has 1152 divisors, whose sum is σ = 309692073600. Its totient is φ = 20827238400.

The previous prime is 81213694823. The next prime is 81213694957. The reversal of 81213694848 is 84849631218.

It is a happy number.

81213694848 is a `hidden beast` number, since 8 + 121 + 36 + 9 + 484 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81213694794 and 81213694803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2619796593 + ... + 2619796623.

It is an arithmetic number, because the mean of its divisors is an integer number (268829925).

Almost surely, 2^81213694848 is an apocalyptic number.

81213694848 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81213694848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154846036800).

81213694848 is an abundant number, since it is smaller than the sum of its proper divisors (228478378752).

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

81213694848 is a wasteful number, since it uses less digits than its factorization.

81213694848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 79 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 54.

The spelling of 81213694848 in words is "eighty-one billion, two hundred thirteen million, six hundred ninety-four thousand, eight hundred forty-eight".