20713856 has 32 divisors (see below), whose sum is σ = 42283080. Its totient is φ = 10101760.

The previous prime is 20713853. The next prime is 20713867. The reversal of 20713856 is 65831702.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20713853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3275 + ... + 7221.

Almost surely, 2^20713856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20713856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21141540).

20713856 is an abundant number, since it is smaller than the sum of its proper divisors (21569224).

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

20713856 is an equidigital number, since it uses as much as digits as its factorization.

20713856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4002 (or 3990 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20713856 is about 4551.2477410047. The cubic root of 20713856 is about 274.6335880400.

The spelling of 20713856 in words is "twenty million, seven hundred thirteen thousand, eight hundred fifty-six".