81077760 has 400 divisors, whose sum is σ = 320845536. Its totient is φ = 19464192.

The previous prime is 81077753. The next prime is 81077761. The reversal of 81077760 is 6777018.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81077761) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3525109 + ... + 3525131.

Almost surely, 2^81077760 is an apocalyptic number.

81077760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81077760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160422768).

81077760 is an abundant number, since it is smaller than the sum of its proper divisors (239767776).

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

81077760 is a wasteful number, since it uses less digits than its factorization.

81077760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 36.

The square root of 81077760 is about 9004.3189636974. The cubic root of 81077760 is about 432.8132827687.

The spelling of 81077760 in words is "eighty-one million, seventy-seven thousand, seven hundred sixty".