665606220 has 24 divisors (see below), whose sum is σ = 1863697584. Its totient is φ = 177494976.

The previous prime is 665606213. The next prime is 665606237. The reversal of 665606220 is 22606566.

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, 5546659 + ... + 5546778.

It is an arithmetic number, because the mean of its divisors is an integer number (77654066).

Almost surely, 2^665606220 is an apocalyptic number.

665606220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665606220 is an abundant number, since it is smaller than the sum of its proper divisors (1198091364).

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

665606220 is a wasteful number, since it uses less digits than its factorization.

665606220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11093449 (or 11093447 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 665606220 is about 25799.3453405314. The cubic root of 665606220 is about 873.1170261775.

The spelling of 665606220 in words is "six hundred sixty-five million, six hundred six thousand, two hundred twenty".