20428128 has 72 divisors (see below), whose sum is σ = 66397968. Its totient is φ = 5836032.

The previous prime is 20428069. The next prime is 20428141. The reversal of 20428128 is 82182402.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 3051 + ... + 7082.

It is an arithmetic number, because the mean of its divisors is an integer number (922194).

Almost surely, 2^20428128 is an apocalyptic number.

20428128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20428128 is an abundant number, since it is smaller than the sum of its proper divisors (45969840).

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

20428128 is a wasteful number, since it uses less digits than its factorization.

20428128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10156 (or 10145 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 20428128 is about 4519.7486655787. The cubic root of 20428128 is about 273.3649669251.

The spelling of 20428128 in words is "twenty million, four hundred twenty-eight thousand, one hundred twenty-eight".