20666688588 has 288 divisors, whose sum is σ = 71665251840. Its totient is φ = 4859688960.

The previous prime is 20666688583. The next prime is 20666688589. The reversal of 20666688588 is 88588666602.

It is a super-2 number, since 2×20666688588² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (20666688583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1048383 + ... + 1067913.

It is an arithmetic number, because the mean of its divisors is an integer number (248837680).

Almost surely, 2^20666688588 is an apocalyptic number.

20666688588 is a gapful number since it is divisible by the number (28) 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 20666688588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35832625920).

20666688588 is an abundant number, since it is smaller than the sum of its proper divisors (50998563252).

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

20666688588 is a wasteful number, since it uses less digits than its factorization.

20666688588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19597 (or 19592 counting only the distinct ones).

The product of its (nonzero) digits is 53084160, while the sum is 63.

The spelling of 20666688588 in words is "twenty billion, six hundred sixty-six million, six hundred eighty-eight thousand, five hundred eighty-eight".