81766280 has 32 divisors (see below), whose sum is σ = 187450200. Its totient is φ = 32088576.

The previous prime is 81766273. The next prime is 81766301. The reversal of 81766280 is 8266718.

It can be written as a sum of positive squares in 4 ways, for example, as 76073284 + 5692996 = 8722^2 + 2386^2 .

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, 17165 + ... + 21404.

Almost surely, 2^81766280 is an apocalyptic number.

It is an amenable number.

81766280 is an abundant number, since it is smaller than the sum of its proper divisors (105683920).

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

81766280 is a wasteful number, since it uses less digits than its factorization.

81766280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38633 (or 38629 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 81766280 is about 9042.4709012526. The cubic root of 81766280 is about 434.0349947360.

The spelling of 81766280 in words is "eighty-one million, seven hundred sixty-six thousand, two hundred eighty".