81202981888 has 198 divisors, whose sum is σ = 199334870316. Its totient is φ = 32962277376.

The previous prime is 81202981841. The next prime is 81202981903. The reversal of 81202981888 is 88818920218.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 18111295 + ... + 18115777.

Almost surely, 2^81202981888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81202981888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99667435158).

81202981888 is an abundant number, since it is smaller than the sum of its proper divisors (118131888428).

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

81202981888 is a wasteful number, since it uses less digits than its factorization.

81202981888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4555 (or 4511 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 55.

The spelling of 81202981888 in words is "eighty-one billion, two hundred two million, nine hundred eighty-one thousand, eight hundred eighty-eight".