20506306 has 8 divisors (see below), whose sum is σ = 31820220. Its totient is φ = 9899568.

The previous prime is 20506303. The next prime is 20506319. The reversal of 20506306 is 60360502.

It can be written as a sum of positive squares in 2 ways, for example, as 19316025 + 1190281 = 4395^2 + 1091^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20506303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176721 + ... + 176836.

Almost surely, 2^20506306 is an apocalyptic number.

20506306 is a deficient number, since it is larger than the sum of its proper divisors (11313914).

20506306 is a wasteful number, since it uses less digits than its factorization.

20506306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353588.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 20506306 is about 4528.3888967270. The cubic root of 20506306 is about 273.7132436072.

Adding to 20506306 its reverse (60360502), we get a palindrome (80866808).

The spelling of 20506306 in words is "twenty million, five hundred six thousand, three hundred six".