81385556616200 has 24 divisors (see below), whose sum is σ = 189221419133130. Its totient is φ = 32554222646400.

The previous prime is 81385556616191. The next prime is 81385556616211. The reversal of 81385556616200 is 261665558318.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 76138992286756 + 5246564329444 = 8725766^2 + 2290538^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 203463891341 + ... + 203463891740.

Almost surely, 2^{81385556616200} is an apocalyptic number.

It is an amenable number.

81385556616200 is an abundant number, since it is smaller than the sum of its proper divisors (107835862516930).

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

81385556616200 is a wasteful number, since it uses less digits than its factorization.

81385556616200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406927783097 (or 406927783088 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 56.

The spelling of 81385556616200 in words is "eighty-one trillion, three hundred eighty-five billion, five hundred fifty-six million, six hundred sixteen thousand, two hundred".