66789898920 has 128 divisors (see below), whose sum is σ = 222972192000. Its totient is φ = 17783504640.

The previous prime is 66789898873. The next prime is 66789898937. The reversal of 66789898920 is 2989898766.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 667101 + ... + 760659.

It is an arithmetic number, because the mean of its divisors is an integer number (1741970250).

Almost surely, 2^66789898920 is an apocalyptic number.

66789898920 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 66789898920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111486096000).

66789898920 is an abundant number, since it is smaller than the sum of its proper divisors (156182293080).

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

66789898920 is a wasteful number, since it uses less digits than its factorization.

66789898920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94240 (or 94230 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 72.

The spelling of 66789898920 in words is "sixty-six billion, seven hundred eighty-nine million, eight hundred ninety-eight thousand, nine hundred twenty".