81061137850 has 192 divisors, whose sum is σ = 194927523840. Its totient is φ = 24335942400.

The previous prime is 81061137827. The next prime is 81061137881. The reversal of 81061137850 is 5873116018.

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, 76256419 + ... + 76257481.

It is an arithmetic number, because the mean of its divisors is an integer number (1015247520).

Almost surely, 2^81061137850 is an apocalyptic number.

81061137850 is an abundant number, since it is smaller than the sum of its proper divisors (113866385990).

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

81061137850 is a wasteful number, since it uses less digits than its factorization.

81061137850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805 (or 1800 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The spelling of 81061137850 in words is "eighty-one billion, sixty-one million, one hundred thirty-seven thousand, eight hundred fifty".