665651180 has 48 divisors (see below), whose sum is σ = 1438002720. Its totient is φ = 258682368.

The previous prime is 665651131. The next prime is 665651197. The reversal of 665651180 is 81156566.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167456 + ... + 171384.

It is an arithmetic number, because the mean of its divisors is an integer number (29958390).

Almost surely, 2^665651180 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665651180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (719001360).

665651180 is an abundant number, since it is smaller than the sum of its proper divisors (772351540).

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

665651180 is a wasteful number, since it uses less digits than its factorization.

665651180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4178 (or 4176 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 665651180 is about 25800.2166657569. The cubic root of 665651180 is about 873.1366846765.

The spelling of 665651180 in words is "six hundred sixty-five million, six hundred fifty-one thousand, one hundred eighty".