81335760 has 80 divisors (see below), whose sum is σ = 275071680. Its totient is φ = 19717120.

The previous prime is 81335743. The next prime is 81335773. The reversal of 81335760 is 6753318.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12765 + ... + 18044.

It is an arithmetic number, because the mean of its divisors is an integer number (3438396).

Almost surely, 2^81335760 is an apocalyptic number.

81335760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81335760 is an abundant number, since it is smaller than the sum of its proper divisors (193735920).

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

81335760 is a wasteful number, since it uses less digits than its factorization.

81335760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30836 (or 30830 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 81335760 is about 9018.6340429136. The cubic root of 81335760 is about 433.2718860932.

The spelling of 81335760 in words is "eighty-one million, three hundred thirty-five thousand, seven hundred sixty".