66204205680 has 160 divisors (see below), whose sum is σ = 220057344000. Its totient is φ = 16405549056.

The previous prime is 66204205651. The next prime is 66204205681. The reversal of 66204205680 is 8650240266.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66204205681) 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, 219621 + ... + 425019.

It is an arithmetic number, because the mean of its divisors is an integer number (1375358400).

Almost surely, 2^66204205680 is an apocalyptic number.

66204205680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66204205680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110028672000).

66204205680 is an abundant number, since it is smaller than the sum of its proper divisors (153853138320).

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

66204205680 is a wasteful number, since it uses less digits than its factorization.

66204205680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205511 (or 205505 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 39.

The spelling of 66204205680 in words is "sixty-six billion, two hundred four million, two hundred five thousand, six hundred eighty".