20345207 has 4 divisors (see below), whose sum is σ = 21001536. Its totient is φ = 19688880.

The previous prime is 20345167. The next prime is 20345231. The reversal of 20345207 is 70254302.

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-20345207 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 (20345267) 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, 328118 + ... + 328179.

It is an arithmetic number, because the mean of its divisors is an integer number (5250384).

Almost surely, 2^20345207 is an apocalyptic number.

20345207 is a deficient number, since it is larger than the sum of its proper divisors (656329).

20345207 is an equidigital number, since it uses as much as digits as its factorization.

20345207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656328.

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 20345207 is about 4510.5661507177. The cubic root of 20345207 is about 272.9945881291.

Adding to 20345207 its reverse (70254302), we get a palindrome (90599509).

The spelling of 20345207 in words is "twenty million, three hundred forty-five thousand, two hundred seven".