665005420 has 12 divisors (see below), whose sum is σ = 1396511424. Its totient is φ = 266002160.

The previous prime is 665005381. The next prime is 665005427. The reversal of 665005420 is 24500566.

It is not an unprimeable number, because it can be changed into a prime (665005427) 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, 16625116 + ... + 16625155.

It is an arithmetic number, because the mean of its divisors is an integer number (116375952).

Almost surely, 2^665005420 is an apocalyptic number.

It is an amenable number.

665005420 is an abundant number, since it is smaller than the sum of its proper divisors (731506004).

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

665005420 is a wasteful number, since it uses less digits than its factorization.

665005420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33250280 (or 33250278 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 665005420 is about 25787.6990055336. The cubic root of 665005420 is about 872.8542448691.

Adding to 665005420 its reverse (24500566), we get a palindrome (689505986).

The spelling of 665005420 in words is "six hundred sixty-five million, five thousand, four hundred twenty".