81249268812 has 24 divisors (see below), whose sum is σ = 189593107200. Its totient is φ = 27081449616.

The previous prime is 81249268781. The next prime is 81249268823. The reversal of 81249268812 is 21886294218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10489 + ... + 403247.

It is an arithmetic number, because the mean of its divisors is an integer number (7899712800).

Almost surely, 2^81249268812 is an apocalyptic number.

It is an amenable number.

81249268812 is an abundant number, since it is smaller than the sum of its proper divisors (108343838388).

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

81249268812 is a wasteful number, since it uses less digits than its factorization.

81249268812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410005 (or 410003 counting only the distinct ones).

The product of its digits is 884736, while the sum is 51.

The spelling of 81249268812 in words is "eighty-one billion, two hundred forty-nine million, two hundred sixty-eight thousand, eight hundred twelve".