20205506 has 8 divisors (see below), whose sum is σ = 30342924. Its totient is φ = 10091200.

The previous prime is 20205487. The next prime is 20205517. The reversal of 20205506 is 60550202.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19722481 + 483025 = 4441^2 + 695^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3395 + ... + 7206.

Almost surely, 2^20205506 is an apocalyptic number.

20205506 is a deficient number, since it is larger than the sum of its proper divisors (10137418).

20205506 is a wasteful number, since it uses less digits than its factorization.

20205506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11556.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20205506 is about 4495.0535035748. The cubic root of 20205506 is about 272.3683105243.

Adding to 20205506 its reverse (60550202), we get a palindrome (80755708).

The spelling of 20205506 in words is "twenty million, two hundred five thousand, five hundred six".