81775760 has 40 divisors (see below), whose sum is σ = 207415296. Its totient is φ = 29736320.

The previous prime is 81775751. The next prime is 81775783. The reversal of 81775760 is 6757718.

It is a tau number, because it is divible by the number of its divisors (40).

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, 45584 + ... + 47343.

Almost surely, 2^81775760 is an apocalyptic number.

81775760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81775760 is an abundant number, since it is smaller than the sum of its proper divisors (125639536).

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

81775760 is a wasteful number, since it uses less digits than its factorization.

81775760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92951 (or 92945 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 41.

The square root of 81775760 is about 9042.9950790653. The cubic root of 81775760 is about 434.0517681245.

The spelling of 81775760 in words is "eighty-one million, seven hundred seventy-five thousand, seven hundred sixty".