20730805 has 16 divisors (see below), whose sum is σ = 26585280. Its totient is φ = 15472512.

The previous prime is 20730799. The next prime is 20730823. The reversal of 20730805 is 50803702.

It is a cyclic number.

It is not a de Polignac number, because 20730805 - 2²¹ = 18633653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20730805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4737 + ... + 7993.

It is an arithmetic number, because the mean of its divisors is an integer number (1661580).

Almost surely, 2^20730805 is an apocalyptic number.

It is an amenable number.

20730805 is a deficient number, since it is larger than the sum of its proper divisors (5854475).

20730805 is a wasteful number, since it uses less digits than its factorization.

20730805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3348.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20730805 is about 4553.1093771180. The cubic root of 20730805 is about 274.7084734320.

The spelling of 20730805 in words is "twenty million, seven hundred thirty thousand, eight hundred five".