80665720 has 32 divisors (see below), whose sum is σ = 187355520. Its totient is φ = 31224960.

The previous prime is 80665703. The next prime is 80665723. The reversal of 80665720 is 2756608.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80665723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31287 + ... + 33766.

It is an arithmetic number, because the mean of its divisors is an integer number (5854860).

Almost surely, 2^80665720 is an apocalyptic number.

It is an amenable number.

80665720 is an abundant number, since it is smaller than the sum of its proper divisors (106689800).

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

80665720 is a wasteful number, since it uses less digits than its factorization.

80665720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65095 (or 65091 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 80665720 is about 8981.4096889074. The cubic root of 80665720 is about 432.0788464909.

The spelling of 80665720 in words is "eighty million, six hundred sixty-five thousand, seven hundred twenty".