81066864 has 20 divisors (see below), whose sum is σ = 209422856. Its totient is φ = 27022272.

The previous prime is 81066859. The next prime is 81066883. The reversal of 81066864 is 46866018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 844399 + ... + 844494.

Almost surely, 2^81066864 is an apocalyptic number.

It is an amenable number.

81066864 is an abundant number, since it is smaller than the sum of its proper divisors (128355992).

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

81066864 is a wasteful number, since it uses less digits than its factorization.

81066864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688904 (or 1688898 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 81066864 is about 9003.7139003858. The cubic root of 81066864 is about 432.7938933792.

The spelling of 81066864 in words is "eighty-one million, sixty-six thousand, eight hundred sixty-four".