81766080 has 336 divisors, whose sum is σ = 320954400. Its totient is φ = 18923520.

The previous prime is 81766079. The next prime is 81766099. The reversal of 81766080 is 8066718.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 918676 + ... + 918764.

Almost surely, 2^81766080 is an apocalyptic number.

81766080 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 81766080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160477200).

81766080 is an abundant number, since it is smaller than the sum of its proper divisors (239188320).

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

81766080 is a wasteful number, since it uses less digits than its factorization.

81766080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 81766080 is about 9042.4598423217. The cubic root of 81766080 is about 434.0346408531.

The spelling of 81766080 in words is "eighty-one million, seven hundred sixty-six thousand, eighty".