20556530 has 16 divisors (see below), whose sum is σ = 37369944. Its totient is φ = 8140800.

The previous prime is 20556521. The next prime is 20556533. The reversal of 20556530 is 3565502.

It can be written as a sum of positive squares in 4 ways, for example, as 19439281 + 1117249 = 4409^2 + 1057^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20556530.

It is not an unprimeable number, because it can be changed into a prime (20556533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9167 + ... + 11186.

Almost surely, 2^20556530 is an apocalyptic number.

20556530 is a deficient number, since it is larger than the sum of its proper divisors (16813414).

20556530 is a wasteful number, since it uses less digits than its factorization.

20556530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20461.

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

The square root of 20556530 is about 4533.9309655088. The cubic root of 20556530 is about 273.9365207164.

The spelling of 20556530 in words is "twenty million, five hundred fifty-six thousand, five hundred thirty".