81853696512000 has 624 divisors, whose sum is σ = 337227374420352. Its totient is φ = 18709408972800.

The previous prime is 81853696511987. The next prime is 81853696512019. The reversal of 81853696512000 is 21569635818.

81853696512000 is a `hidden beast` number, since 8 + 1 + 8 + 5 + 36 + 96 + 512 + 0 + 0 + 0 = 666.

It is a super-2 number, since 2×81853696512000² (a number of 29 digits) contains 22 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, 30987187 + ... + 33524813.

It is an arithmetic number, because the mean of its divisors is an integer number (540428484648).

Almost surely, 2^{81853696512000} is an apocalyptic number.

81853696512000 is a gapful number since it is divisible by the number (80) 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 81853696512000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168613687210176).

81853696512000 is an abundant number, since it is smaller than the sum of its proper divisors (255373677908352).

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

81853696512000 is a wasteful number, since it uses less digits than its factorization.

81853696512000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2537679 (or 2537644 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The spelling of 81853696512000 in words is "eighty-one trillion, eight hundred fifty-three billion, six hundred ninety-six million, five hundred twelve thousand".