665547940 has 12 divisors (see below), whose sum is σ = 1397650716. Its totient is φ = 266219168.

The previous prime is 665547931. The next prime is 665547947. The reversal of 665547940 is 49745566.

It can be written as a sum of positive squares in 2 ways, for example, as 364733604 + 300814336 = 19098^2 + 17344^2 .

It is not an unprimeable number, because it can be changed into a prime (665547947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16638679 + ... + 16638718.

It is an arithmetic number, because the mean of its divisors is an integer number (116470893).

Almost surely, 2^665547940 is an apocalyptic number.

It is an amenable number.

665547940 is an abundant number, since it is smaller than the sum of its proper divisors (732102776).

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

665547940 is a wasteful number, since it uses less digits than its factorization.

665547940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33277406 (or 33277404 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The square root of 665547940 is about 25798.2158297817. The cubic root of 665547940 is about 873.0915422682.

The spelling of 665547940 in words is "six hundred sixty-five million, five hundred forty-seven thousand, nine hundred forty".