20805349 has 8 divisors (see below), whose sum is σ = 21375360. Its totient is φ = 20240736.

The previous prime is 20805341. The next prime is 20805353. The reversal of 20805349 is 94350802.

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 20805349 - 2³ = 20805341 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20805349.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20805341) 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, 7177 + ... + 9649.

It is an arithmetic number, because the mean of its divisors is an integer number (2671920).

Almost surely, 2^20805349 is an apocalyptic number.

It is an amenable number.

20805349 is a deficient number, since it is larger than the sum of its proper divisors (570011).

20805349 is a wasteful number, since it uses less digits than its factorization.

20805349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2699.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20805349 is about 4561.2880856179. The cubic root of 20805349 is about 275.0373458923.

The spelling of 20805349 in words is "twenty million, eight hundred five thousand, three hundred forty-nine".