666726322020 has 96 divisors (see below), whose sum is σ = 2036684805120. Its totient is φ = 161619596160.

The previous prime is 666726322001. The next prime is 666726322027. The reversal of 666726322020 is 20223627666.

It is not an unprimeable number, because it can be changed into a prime (666726322027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13930491 + ... + 13978269.

It is an arithmetic number, because the mean of its divisors is an integer number (21215466720).

Almost surely, 2^666726322020 is an apocalyptic number.

666726322020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666726322020 is an abundant number, since it is smaller than the sum of its proper divisors (1369958483100).

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

666726322020 is a wasteful number, since it uses less digits than its factorization.

666726322020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68945 (or 68943 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 42.

Adding to 666726322020 its reverse (20223627666), we get a palindrome (686949949686).

The spelling of 666726322020 in words is "six hundred sixty-six billion, seven hundred twenty-six million, three hundred twenty-two thousand, twenty".