20928040 has 64 divisors (see below), whose sum is σ = 55157760. Its totient is φ = 6996480.

The previous prime is 20928029. The next prime is 20928043. The reversal of 20928040 is 4082902.

It is a junction number, because it is equal to n+sod(n) for n = 20927996 and 20928014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20928043) 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 15 ways as a sum of consecutive naturals, for example, 10569 + ... + 12391.

It is an arithmetic number, because the mean of its divisors is an integer number (861840).

Almost surely, 2^20928040 is an apocalyptic number.

20928040 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 20928040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27578880).

20928040 is an abundant number, since it is smaller than the sum of its proper divisors (34229720).

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

20928040 is a wasteful number, since it uses less digits than its factorization.

20928040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882 (or 1878 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20928040 is about 4574.7174776154. The cubic root of 20928040 is about 275.5769265519.

The spelling of 20928040 in words is "twenty million, nine hundred twenty-eight thousand, forty".