81764180 has 12 divisors (see below), whose sum is σ = 171704820. Its totient is φ = 32705664.

The previous prime is 81764171. The next prime is 81764261. The reversal of 81764180 is 8146718.

It can be written as a sum of positive squares in 2 ways, for example, as 54848836 + 26915344 = 7406^2 + 5188^2 .

It is a super-2 number, since 2×81764180² = 13370762262144800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81764180.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2044085 + ... + 2044124.

It is an arithmetic number, because the mean of its divisors is an integer number (14308735).

Almost surely, 2^81764180 is an apocalyptic number.

It is an amenable number.

81764180 is an abundant number, since it is smaller than the sum of its proper divisors (89940640).

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

81764180 is a wasteful number, since it uses less digits than its factorization.

81764180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4088218 (or 4088216 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 81764180 is about 9042.3547818032. The cubic root of 81764180 is about 434.0312789366.

The spelling of 81764180 in words is "eighty-one million, seven hundred sixty-four thousand, one hundred eighty".