81760520 has 16 divisors (see below), whose sum is σ = 183961260. Its totient is φ = 32704192.

The previous prime is 81760517. The next prime is 81760529. The reversal of 81760520 is 2506718.

It can be written as a sum of positive squares in 2 ways, for example, as 81685444 + 75076 = 9038^2 + 274^2 .

It is not an unprimeable number, because it can be changed into a prime (81760529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1021967 + ... + 1022046.

Almost surely, 2^81760520 is an apocalyptic number.

It is an amenable number.

81760520 is an abundant number, since it is smaller than the sum of its proper divisors (102200740).

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

81760520 is a wasteful number, since it uses less digits than its factorization.

81760520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2044024 (or 2044020 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 81760520 is about 9042.1523986272. The cubic root of 81760520 is about 434.0248026769.

The spelling of 81760520 in words is "eighty-one million, seven hundred sixty thousand, five hundred twenty".