20905525 has 12 divisors (see below), whose sum is σ = 26527072. Its totient is φ = 16334640.

The previous prime is 20905519. The next prime is 20905559. The reversal of 20905525 is 52550902.

It is not a de Polignac number, because 20905525 - 2³ = 20905517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20905493 and 20905502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8649 + ... + 10798.

Almost surely, 2^20905525 is an apocalyptic number.

20905525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20905525 is a deficient number, since it is larger than the sum of its proper divisors (5621547).

20905525 is a wasteful number, since it uses less digits than its factorization.

20905525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19500 (or 19495 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 20905525 is about 4572.2560077056. The cubic root of 20905525 is about 275.4780665079.

The spelling of 20905525 in words is "twenty million, nine hundred five thousand, five hundred twenty-five".