20506207 has 4 divisors (see below), whose sum is σ = 20523520. Its totient is φ = 20488896.

The previous prime is 20506201. The next prime is 20506243. The reversal of 20506207 is 70260502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20506207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506201) 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, 6738 + ... + 9295.

It is an arithmetic number, because the mean of its divisors is an integer number (5130880).

Almost surely, 2^20506207 is an apocalyptic number.

20506207 is a deficient number, since it is larger than the sum of its proper divisors (17313).

20506207 is a wasteful number, since it uses less digits than its factorization.

20506207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17312.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20506207 is about 4528.3779656738. The cubic root of 20506207 is about 273.7128031304.

Adding to 20506207 its reverse (70260502), we get a palindrome (90766709).

The spelling of 20506207 in words is "twenty million, five hundred six thousand, two hundred seven".