20405525 has 48 divisors (see below), whose sum is σ = 32319360. Its totient is φ = 12476160.

The previous prime is 20405513. The next prime is 20405527. The reversal of 20405525 is 52550402.

It is not a de Polignac number, because 20405525 - 2⁶ = 20405461 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20405525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20405527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1073966 + ... + 1073984.

It is an arithmetic number, because the mean of its divisors is an integer number (673320).

Almost surely, 2^20405525 is an apocalyptic number.

20405525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20405525 is a deficient number, since it is larger than the sum of its proper divisors (11913835).

20405525 is an equidigital number, since it uses as much as digits as its factorization.

20405525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 23.

The square root of 20405525 is about 4517.2475026281. The cubic root of 20405525 is about 273.2641068324.

Adding to 20405525 its reverse (52550402), we get a palindrome (72955927).

The spelling of 20405525 in words is "twenty million, four hundred five thousand, five hundred twenty-five".