20128566 has 8 divisors (see below), whose sum is σ = 40257144. Its totient is φ = 6709520.

The previous prime is 20128553. The next prime is 20128573. The reversal of 20128566 is 66582102.

It is a sphenic number, since it is the product of 3 distinct primes.

20128566 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1677375 + ... + 1677386.

It is an arithmetic number, because the mean of its divisors is an integer number (5032143).

Almost surely, 2^20128566 is an apocalyptic number.

20128566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20128566 is a wasteful number, since it uses less digits than its factorization.

20128566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3354766.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20128566 is about 4486.4870444480. The cubic root of 20128566 is about 272.0221561393.

The spelling of 20128566 in words is "twenty million, one hundred twenty-eight thousand, five hundred sixty-six".