81081299487312 has 120 divisors (see below), whose sum is σ = 245850479544384. Its totient is φ = 24845705966592.

The previous prime is 81081299487263. The next prime is 81081299487323. The reversal of 81081299487312 is 21378499218018.

81081299487312 is a `hidden beast` number, since 8 + 10 + 8 + 129 + 9 + 487 + 3 + 12 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81081299487312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 385027828 + ... + 385238355.

Almost surely, 2^{81081299487312} is an apocalyptic number.

It is an amenable number.

81081299487312 is an abundant number, since it is smaller than the sum of its proper divisors (164769180057072).

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

81081299487312 is a wasteful number, since it uses less digits than its factorization.

81081299487312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770266257 (or 770266248 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 63.

The spelling of 81081299487312 in words is "eighty-one trillion, eighty-one billion, two hundred ninety-nine million, four hundred eighty-seven thousand, three hundred twelve".