20685760 has 56 divisors (see below), whose sum is σ = 49743360. Its totient is φ = 8193024.

The previous prime is 20685733. The next prime is 20685811. The reversal of 20685760 is 6758602.

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, 40386 + ... + 40894.

Almost surely, 2^20685760 is an apocalyptic number.

20685760 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 20685760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24871680).

20685760 is an abundant number, since it is smaller than the sum of its proper divisors (29057600).

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

20685760 is a wasteful number, since it uses less digits than its factorization.

20685760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 20685760 is about 4548.1600675438. The cubic root of 20685760 is about 274.5093620695.

The spelling of 20685760 in words is "twenty million, six hundred eighty-five thousand, seven hundred sixty".