66205420 has 12 divisors (see below), whose sum is σ = 139031424. Its totient is φ = 26482160.

The previous prime is 66205417. The next prime is 66205421. The reversal of 66205420 is 2450266.

It is not an unprimeable number, because it can be changed into a prime (66205421) 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, 1655116 + ... + 1655155.

It is an arithmetic number, because the mean of its divisors is an integer number (11585952).

Almost surely, 2^66205420 is an apocalyptic number.

It is an amenable number.

66205420 is an abundant number, since it is smaller than the sum of its proper divisors (72826004).

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

66205420 is a wasteful number, since it uses less digits than its factorization.

66205420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3310280 (or 3310278 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 66205420 is about 8136.6713095713. The cubic root of 66205420 is about 404.5428362794.

Adding to 66205420 its reverse (2450266), we get a palindrome (68655686).

The spelling of 66205420 in words is "sixty-six million, two hundred five thousand, four hundred twenty".