20713728 has 72 divisors (see below), whose sum is σ = 63020608. Its totient is φ = 5916672.

The previous prime is 20713703. The next prime is 20713741. The reversal of 20713728 is 82731702.

It is a junction number, because it is equal to n+sod(n) for n = 20713695 and 20713704.

It is an unprimeable number.

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, 3450 + ... + 7302.

Almost surely, 2^20713728 is an apocalyptic number.

20713728 is a gapful number since it is divisible by the number (28) 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 20713728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31510304).

20713728 is an abundant number, since it is smaller than the sum of its proper divisors (42306880).

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

20713728 is an equidigital number, since it uses as much as digits as its factorization.

20713728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3879 (or 3865 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 20713728 is about 4551.2336789051. The cubic root of 20713728 is about 274.6330223450.

The spelling of 20713728 in words is "twenty million, seven hundred thirteen thousand, seven hundred twenty-eight".