20128564 has 12 divisors (see below), whose sum is σ = 35281764. Its totient is φ = 10048064.

The previous prime is 20128553. The next prime is 20128573. The reversal of 20128564 is 46582102.

It can be written as a sum of positive squares in 2 ways, for example, as 11764900 + 8363664 = 3430^2 + 2892^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1009 + ... + 6424.

It is an arithmetic number, because the mean of its divisors is an integer number (2940147).

Almost surely, 2^20128564 is an apocalyptic number.

It is an amenable number.

20128564 is a deficient number, since it is larger than the sum of its proper divisors (15153200).

20128564 is a wasteful number, since it uses less digits than its factorization.

20128564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8114 (or 8112 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 20128564 is about 4486.4868215565. The cubic root of 20128564 is about 272.0221471298.

The spelling of 20128564 in words is "twenty million, one hundred twenty-eight thousand, five hundred sixty-four".