81651056712 has 192 divisors, whose sum is σ = 231550894080. Its totient is φ = 23930446848.

The previous prime is 81651056701. The next prime is 81651056713. The reversal of 81651056712 is 21765015618.

It is not an unprimeable number, because it can be changed into a prime (81651056713) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6853753 + ... + 6865655.

It is an arithmetic number, because the mean of its divisors is an integer number (1205994240).

Almost surely, 2^81651056712 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 81651056712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115775447040).

81651056712 is an abundant number, since it is smaller than the sum of its proper divisors (149899837368).

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

81651056712 is a wasteful number, since it uses less digits than its factorization.

81651056712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12012 (or 11991 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 42.

The spelling of 81651056712 in words is "eighty-one billion, six hundred fifty-one million, fifty-six thousand, seven hundred twelve".