20668538880 has 448 divisors, whose sum is σ = 80211168000. Its totient is φ = 5007605760.

The previous prime is 20668538867. The next prime is 20668538881. The reversal of 20668538880 is 8883586602.

20668538880 is a `hidden beast` number, since 20 + 6 + 6 + 8 + 538 + 8 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20668538881) 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, 12164271 + ... + 12165969.

Almost surely, 2^20668538880 is an apocalyptic number.

20668538880 is a gapful number since it is divisible by the number (20) 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 20668538880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40105584000).

20668538880 is an abundant number, since it is smaller than the sum of its proper divisors (59542629120).

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

20668538880 is a wasteful number, since it uses less digits than its factorization.

20668538880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1750 (or 1720 counting only the distinct ones).

The product of its (nonzero) digits is 4423680, while the sum is 54.

The spelling of 20668538880 in words is "twenty billion, six hundred sixty-eight million, five hundred thirty-eight thousand, eight hundred eighty".