20128425 has 24 divisors (see below), whose sum is σ = 35238816. Its totient is φ = 10103040.

The previous prime is 20128421. The next prime is 20128439. The reversal of 20128425 is 52482102.

It is not a de Polignac number, because 20128425 - 2² = 20128421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20128395 and 20128404.

It is not an unprimeable number, because it can be changed into a prime (20128421) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 6619 + ... + 9168.

It is an arithmetic number, because the mean of its divisors is an integer number (1468284).

Almost surely, 2^20128425 is an apocalyptic number.

20128425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20128425 is a deficient number, since it is larger than the sum of its proper divisors (15110391).

20128425 is a wasteful number, since it uses less digits than its factorization.

20128425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15817 (or 15812 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 20128425 is about 4486.4713305670. The cubic root of 20128425 is about 272.0215209688.

The spelling of 20128425 in words is "twenty million, one hundred twenty-eight thousand, four hundred twenty-five".