20689760 has 192 divisors, whose sum is σ = 63504000. Its totient is φ = 6322176.

The previous prime is 20689709. The next prime is 20689763. The reversal of 20689760 is 6798602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 713426 + ... + 713454.

It is an arithmetic number, because the mean of its divisors is an integer number (330750).

Almost surely, 2^20689760 is an apocalyptic number.

20689760 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 20689760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31752000).

20689760 is an abundant number, since it is smaller than the sum of its proper divisors (42814240).

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

20689760 is a wasteful number, since it uses less digits than its factorization.

20689760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 56 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 20689760 is about 4548.5997845491. The cubic root of 20689760 is about 274.5270548636.

The spelling of 20689760 in words is "twenty million, six hundred eighty-nine thousand, seven hundred sixty".