81584066 has 8 divisors (see below), whose sum is σ = 124685244. Its totient is φ = 40022320.

The previous prime is 81584053. The next prime is 81584077. The reversal of 81584066 is 66048518.

It can be written as a sum of positive squares in 2 ways, for example, as 80910025 + 674041 = 8995^2 + 821^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon 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, 384725 + ... + 384936.

Almost surely, 2^81584066 is an apocalyptic number.

81584066 is a deficient number, since it is larger than the sum of its proper divisors (43101178).

81584066 is a wasteful number, since it uses less digits than its factorization.

81584066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769716.

The product of its (nonzero) digits is 46080, while the sum is 38.

The square root of 81584066 is about 9032.3898277256. The cubic root of 81584066 is about 433.7123430948.

The spelling of 81584066 in words is "eighty-one million, five hundred eighty-four thousand, sixty-six".