20500557 has 16 divisors (see below), whose sum is σ = 34079232. Its totient is φ = 10649520.

The previous prime is 20500541. The next prime is 20500577. The reversal of 20500557 is 75500502.

It is not a de Polignac number, because 20500557 - 2⁴ = 20500541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20500577) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 44143 + ... + 44604.

It is an arithmetic number, because the mean of its divisors is an integer number (2129952).

Almost surely, 2^20500557 is an apocalyptic number.

It is an amenable number.

20500557 is a deficient number, since it is larger than the sum of its proper divisors (13578675).

20500557 is a wasteful number, since it uses less digits than its factorization.

20500557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88768.

The product of its (nonzero) digits is 1750, while the sum is 24.

The square root of 20500557 is about 4527.7540790109. The cubic root of 20500557 is about 273.6876624597.

Subtracting 20500557 from its reverse (75500502), we obtain a palindrome (54999945).

The spelling of 20500557 in words is "twenty million, five hundred thousand, five hundred fifty-seven".