20505606 has 32 divisors (see below), whose sum is σ = 45214848. Its totient is φ = 6147840.

The previous prime is 20505599. The next prime is 20505619. The reversal of 20505606 is 60650502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4801 + ... + 8003.

It is an arithmetic number, because the mean of its divisors is an integer number (1412964).

Almost surely, 2^20505606 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20505606, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22607424).

20505606 is an abundant number, since it is smaller than the sum of its proper divisors (24709242).

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

20505606 is a wasteful number, since it uses less digits than its factorization.

20505606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3316.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 20505606 is about 4528.3116058858. The cubic root of 20505606 is about 273.7101290945.

Subtracting 20505606 from its reverse (60650502), we obtain a square (40144896 = 6336²).

The spelling of 20505606 in words is "twenty million, five hundred five thousand, six hundred six".