20505625 has 40 divisors (see below), whose sum is σ = 30240320. Its totient is φ = 13608000.

The previous prime is 20505623. The next prime is 20505643. The reversal of 20505625 is 52650502.

It is not a de Polignac number, because 20505625 - 2¹ = 20505623 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 20505625.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505623) 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 39 ways as a sum of consecutive naturals, for example, 188071 + ... + 188179.

It is an arithmetic number, because the mean of its divisors is an integer number (756008).

Almost surely, 2^20505625 is an apocalyptic number.

20505625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20505625 is a deficient number, since it is larger than the sum of its proper divisors (9734695).

20505625 is an equidigital number, since it uses as much as digits as its factorization.

20505625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 20505625 is about 4528.3137037975. The cubic root of 20505625 is about 273.7102136322.

The spelling of 20505625 in words is "twenty million, five hundred five thousand, six hundred twenty-five".