66000020 has 12 divisors (see below), whose sum is σ = 138600084. Its totient is φ = 26400000.

The previous prime is 66000013. The next prime is 66000029. The reversal of 66000020 is 2000066.

It can be written as a sum of positive squares in 2 ways, for example, as 50523664 + 15476356 = 7108^2 + 3934^2 .

It is a hoax number, since the sum of its digits (14) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 65999959 and 66000004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66000029) 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, 1649981 + ... + 1650020.

It is an arithmetic number, because the mean of its divisors is an integer number (11550007).

Almost surely, 2^66000020 is an apocalyptic number.

It is an amenable number.

66000020 is an abundant number, since it is smaller than the sum of its proper divisors (72600064).

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

66000020 is a wasteful number, since it uses less digits than its factorization.

66000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3300010 (or 3300008 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 66000020 is about 8124.0396355508. The cubic root of 66000020 is about 404.1240428828.

Adding to 66000020 its reverse (2000066), we get a palindrome (68000086).

The spelling of 66000020 in words is "sixty-six million, twenty", and thus it is an aban number and an uban number.