20505536 has 56 divisors (see below), whose sum is σ = 44110656. Its totient is φ = 9420800.

The previous prime is 20505497. The next prime is 20505571. The reversal of 20505536 is 63550502.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 50936 + ... + 51336.

Almost surely, 2^20505536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20505536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22055328).

20505536 is an abundant number, since it is smaller than the sum of its proper divisors (23605120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20505536 is a wasteful number, since it uses less digits than its factorization.

20505536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477 (or 467 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 26.

The square root of 20505536 is about 4528.3038767291. The cubic root of 20505536 is about 273.7098176393.

The spelling of 20505536 in words is "twenty million, five hundred five thousand, five hundred thirty-six".