66680020 has 24 divisors (see below), whose sum is σ = 152758368. Its totient is φ = 24247200.

The previous prime is 66680011. The next prime is 66680021. The reversal of 66680020 is 2008666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66680021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151326 + ... + 151765.

It is an arithmetic number, because the mean of its divisors is an integer number (6364932).

Almost surely, 2^66680020 is an apocalyptic number.

It is an amenable number.

66680020 is an abundant number, since it is smaller than the sum of its proper divisors (86078348).

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

66680020 is a wasteful number, since it uses less digits than its factorization.

66680020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303111 (or 303109 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 66680020 is about 8165.7834896598. The cubic root of 66680020 is about 405.5072037878.

Adding to 66680020 its reverse (2008666), we get a palindrome (68688686).

It can be divided in two parts, 66 and 680020, that added together give a palindrome (680086).

The spelling of 66680020 in words is "sixty-six million, six hundred eighty thousand, twenty".