20805308 has 6 divisors (see below), whose sum is σ = 36409296. Its totient is φ = 10402652.

The previous prime is 20805307. The next prime is 20805329. The reversal of 20805308 is 80350802.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20805307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2600660 + ... + 2600667.

It is an arithmetic number, because the mean of its divisors is an integer number (6068216).

Almost surely, 2^20805308 is an apocalyptic number.

It is an amenable number.

20805308 is a deficient number, since it is larger than the sum of its proper divisors (15603988).

20805308 is a wasteful number, since it uses less digits than its factorization.

20805308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5201331 (or 5201329 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 20805308 is about 4561.2835912712. The cubic root of 20805308 is about 275.0371652250.

The spelling of 20805308 in words is "twenty million, eight hundred five thousand, three hundred eight".