81077712 has 60 divisors (see below), whose sum is σ = 221101920. Its totient is φ = 25598016.

The previous prime is 81077699. The next prime is 81077713. The reversal of 81077712 is 21777018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81077713) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14989 + ... + 19667.

It is an arithmetic number, because the mean of its divisors is an integer number (3685032).

Almost surely, 2^81077712 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 81077712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110550960).

81077712 is an abundant number, since it is smaller than the sum of its proper divisors (140024208).

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

81077712 is a wasteful number, since it uses less digits than its factorization.

81077712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4728 (or 4703 counting only the distinct ones).

The product of its (nonzero) digits is 5488, while the sum is 33.

The square root of 81077712 is about 9004.3162983094. The cubic root of 81077712 is about 432.8131973567.

The spelling of 81077712 in words is "eighty-one million, seventy-seven thousand, seven hundred twelve".