81756960 has 48 divisors (see below), whose sum is σ = 257535936. Its totient is φ = 21801728.

The previous prime is 81756907. The next prime is 81757009. The reversal of 81756960 is 6965718.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84684 + ... + 85643.

It is an arithmetic number, because the mean of its divisors is an integer number (5365332).

Almost surely, 2^81756960 is an apocalyptic number.

81756960 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81756960 is an abundant number, since it is smaller than the sum of its proper divisors (175778976).

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

81756960 is a wasteful number, since it uses less digits than its factorization.

81756960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170345 (or 170337 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 81756960 is about 9041.9555407003. The cubic root of 81756960 is about 434.0185031788.

The spelling of 81756960 in words is "eighty-one million, seven hundred fifty-six thousand, nine hundred sixty".