20711680 has 72 divisors (see below), whose sum is σ = 54157824. Its totient is φ = 7526400.

The previous prime is 20711671. The next prime is 20711687. The reversal of 20711680 is 8611702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20711687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13345 + ... + 14815.

It is an arithmetic number, because the mean of its divisors is an integer number (752192).

Almost surely, 2^20711680 is an apocalyptic number.

20711680 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 20711680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27078912).

20711680 is an abundant number, since it is smaller than the sum of its proper divisors (33446144).

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

20711680 is a wasteful number, since it uses less digits than its factorization.

20711680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503 (or 1489 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 20711680 is about 4551.0086794028. The cubic root of 20711680 is about 274.6239709087.

The spelling of 20711680 in words is "twenty million, seven hundred eleven thousand, six hundred eighty".