20928280 has 16 divisors (see below), whose sum is σ = 47088720. Its totient is φ = 8371296.

The previous prime is 20928251. The next prime is 20928283. The reversal of 20928280 is 8282902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20928283) 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, 261564 + ... + 261643.

It is an arithmetic number, because the mean of its divisors is an integer number (2943045).

Almost surely, 2^20928280 is an apocalyptic number.

20928280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20928280 is an abundant number, since it is smaller than the sum of its proper divisors (26160440).

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

20928280 is a wasteful number, since it uses less digits than its factorization.

20928280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523218 (or 523214 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 20928280 is about 4574.7437086683. The cubic root of 20928280 is about 275.5779799745.

The spelling of 20928280 in words is "twenty million, nine hundred twenty-eight thousand, two hundred eighty".