20526561 has 48 divisors (see below), whose sum is σ = 34303360. Its totient is φ = 12117600.

The previous prime is 20526551. The next prime is 20526607. The reversal of 20526561 is 16562502.

20526561 is a `hidden beast` number, since 2 + 0 + 5 + 2 + 656 + 1 = 666.

It is not a de Polignac number, because 20526561 - 2⁹ = 20526049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20526551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 199236 + ... + 199338.

Almost surely, 2^20526561 is an apocalyptic number.

It is an amenable number.

20526561 is a deficient number, since it is larger than the sum of its proper divisors (13776799).

20526561 is a wasteful number, since it uses less digits than its factorization.

20526561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 20526561 is about 4530.6247913505. The cubic root of 20526561 is about 273.8033335755.

The spelling of 20526561 in words is "twenty million, five hundred twenty-six thousand, five hundred sixty-one".