20889561688 has 32 divisors (see below), whose sum is σ = 39311548560. Its totient is φ = 10406556160.

The previous prime is 20889561661. The next prime is 20889561731. The reversal of 20889561688 is 88616598802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2567595 + ... + 2575717.

Almost surely, 2^20889561688 is an apocalyptic number.

It is an amenable number.

20889561688 is a deficient number, since it is larger than the sum of its proper divisors (18421986872).

20889561688 is a wasteful number, since it uses less digits than its factorization.

20889561688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9267 (or 9263 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 61.

The spelling of 20889561688 in words is "twenty billion, eight hundred eighty-nine million, five hundred sixty-one thousand, six hundred eighty-eight".