20309207 has 8 divisors (see below), whose sum is σ = 21389280. Its totient is φ = 19245600.

The previous prime is 20309183. The next prime is 20309209. The reversal of 20309207 is 70290302.

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

It is a cyclic number.

It is not a de Polignac number, because 20309207 - 2⁶ = 20309143 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309209) 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, 1544 + ... + 6557.

It is an arithmetic number, because the mean of its divisors is an integer number (2673660).

Almost surely, 2^20309207 is an apocalyptic number.

20309207 is a deficient number, since it is larger than the sum of its proper divisors (1080073).

20309207 is a wasteful number, since it uses less digits than its factorization.

20309207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8233.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 20309207 is about 4506.5737539732. The cubic root of 20309207 is about 272.8334755304.

Adding to 20309207 its reverse (70290302), we get a palindrome (90599509).

The spelling of 20309207 in words is "twenty million, three hundred nine thousand, two hundred seven".