20898788664 has 64 divisors (see below), whose sum is σ = 56423001600. Its totient is φ = 6412450176.

The previous prime is 20898788641. The next prime is 20898788671. The reversal of 20898788664 is 46688789802.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20898788595 and 20898788604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18717 + ... + 205299.

It is an arithmetic number, because the mean of its divisors is an integer number (881609400).

Almost surely, 2^20898788664 is an apocalyptic number.

20898788664 is a gapful number since it is divisible by the number (24) 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 20898788664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28211500800).

20898788664 is an abundant number, since it is smaller than the sum of its proper divisors (35524212936).

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

20898788664 is a wasteful number, since it uses less digits than its factorization.

20898788664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186964 (or 186960 counting only the distinct ones).

The product of its (nonzero) digits is 74317824, while the sum is 66.

The spelling of 20898788664 in words is "twenty billion, eight hundred ninety-eight million, seven hundred eighty-eight thousand, six hundred sixty-four".