20307205 has 16 divisors (see below), whose sum is σ = 24998400. Its totient is φ = 15831360.

The previous prime is 20307179. The next prime is 20307233. The reversal of 20307205 is 50270302.

It is a happy number.

It is not a de Polignac number, because 20307205 - 2²³ = 11918597 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42156 + ... + 42634.

It is an arithmetic number, because the mean of its divisors is an integer number (1562400).

Almost surely, 2^20307205 is an apocalyptic number.

It is an amenable number.

20307205 is a deficient number, since it is larger than the sum of its proper divisors (4691195).

20307205 is a wasteful number, since it uses less digits than its factorization.

20307205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684.

The product of its (nonzero) digits is 420, while the sum is 19.

The square root of 20307205 is about 4506.3516285350. The cubic root of 20307205 is about 272.8245102933.

Adding to 20307205 its reverse (50270302), we get a palindrome (70577507).

The spelling of 20307205 in words is "twenty million, three hundred seven thousand, two hundred five".