81547704000 has 672 divisors, whose sum is σ = 342471182976. Its totient is φ = 18131558400.

The previous prime is 81547703953. The next prime is 81547704013. The reversal of 81547704000 is 40774518.

81547704000 is a `hidden beast` number, since 8 + 1 + 547 + 70 + 40 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18645814 + ... + 18650186.

Almost surely, 2^81547704000 is an apocalyptic number.

81547704000 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 81547704000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171235591488).

81547704000 is an abundant number, since it is smaller than the sum of its proper divisors (260923478976).

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

81547704000 is a wasteful number, since it uses less digits than its factorization.

81547704000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4450 (or 4427 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The spelling of 81547704000 in words is "eighty-one billion, five hundred forty-seven million, seven hundred four thousand".