66650020 has 12 divisors (see below), whose sum is σ = 139965084. Its totient is φ = 26660000.

The previous prime is 66649993. The next prime is 66650027. The reversal of 66650020 is 2005666.

It can be written as a sum of positive squares in 2 ways, for example, as 43243776 + 23406244 = 6576^2 + 4838^2 .

It is not an unprimeable number, because it can be changed into a prime (66650027) 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, 1666231 + ... + 1666270.

It is an arithmetic number, because the mean of its divisors is an integer number (11663757).

Almost surely, 2^66650020 is an apocalyptic number.

It is an amenable number.

66650020 is an abundant number, since it is smaller than the sum of its proper divisors (73315064).

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

66650020 is a wasteful number, since it uses less digits than its factorization.

66650020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332510 (or 3332508 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 66650020 is about 8163.9463496522. The cubic root of 66650020 is about 405.4463807657.

Adding to 66650020 its reverse (2005666), we get a palindrome (68655686).

The spelling of 66650020 in words is "sixty-six million, six hundred fifty thousand, twenty".