81732666 has 16 divisors (see below), whose sum is σ = 163994688. Its totient is φ = 27156000.

The previous prime is 81732649. The next prime is 81732713. The reversal of 81732666 is 66623718.

It is a Curzon number.

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, 20035 + ... + 23766.

It is an arithmetic number, because the mean of its divisors is an integer number (10249668).

Almost surely, 2^81732666 is an apocalyptic number.

81732666 is an abundant number, since it is smaller than the sum of its proper divisors (82262022).

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

81732666 is a wasteful number, since it uses less digits than its factorization.

81732666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44117.

The product of its digits is 72576, while the sum is 39.

The square root of 81732666 is about 9040.6120368037. The cubic root of 81732666 is about 433.9755095300.

The spelling of 81732666 in words is "eighty-one million, seven hundred thirty-two thousand, six hundred sixty-six".