81930066 has 16 divisors (see below), whose sum is σ = 164143584. Its totient is φ = 27262784.

The previous prime is 81930049. The next prime is 81930073. The reversal of 81930066 is 66003918.

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, 7956 + ... + 15071.

It is an arithmetic number, because the mean of its divisors is an integer number (10258974).

Almost surely, 2^81930066 is an apocalyptic number.

81930066 is an abundant number, since it is smaller than the sum of its proper divisors (82213518).

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

81930066 is a wasteful number, since it uses less digits than its factorization.

81930066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23625.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 81930066 is about 9051.5228552990. The cubic root of 81930066 is about 434.3246065515.

The spelling of 81930066 in words is "eighty-one million, nine hundred thirty thousand, sixty-six".