81057636000 has 576 divisors, whose sum is σ = 316924223616. Its totient is φ = 19456512000.

The previous prime is 81057635963. The next prime is 81057636007. The reversal of 81057636000 is 63675018.

81057636000 is a `hidden beast` number, since 8 + 10 + 5 + 7 + 636 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81057636007) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 42371044 + ... + 42372956.

It is an arithmetic number, because the mean of its divisors is an integer number (550215666).

Almost surely, 2^81057636000 is an apocalyptic number.

81057636000 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 81057636000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158462111808).

81057636000 is an abundant number, since it is smaller than the sum of its proper divisors (235866587616).

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

81057636000 is a wasteful number, since it uses less digits than its factorization.

81057636000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2062 (or 2041 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 81057636000 in words is "eighty-one billion, fifty-seven million, six hundred thirty-six thousand".