81544915012 has 48 divisors (see below), whose sum is σ = 157774780800. Its totient is φ = 36569007360.

The previous prime is 81544915003. The next prime is 81544915031. The reversal of 81544915012 is 21051944518.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1185664 + ... + 1252552.

It is an arithmetic number, because the mean of its divisors is an integer number (3286974600).

Almost surely, 2^81544915012 is an apocalyptic number.

It is an amenable number.

81544915012 is a deficient number, since it is larger than the sum of its proper divisors (76229865788).

81544915012 is a wasteful number, since it uses less digits than its factorization.

81544915012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67276 (or 67274 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 40.

The spelling of 81544915012 in words is "eighty-one billion, five hundred forty-four million, nine hundred fifteen thousand, twelve".