20820205 has 16 divisors (see below), whose sum is σ = 28650240. Its totient is φ = 14228352.

The previous prime is 20820203. The next prime is 20820211. The reversal of 20820205 is 50202802.

It is a cyclic number.

It is not a de Polignac number, because 20820205 - 2¹ = 20820203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11737 + ... + 13393.

It is an arithmetic number, because the mean of its divisors is an integer number (1790640).

Almost surely, 2^20820205 is an apocalyptic number.

It is an amenable number.

20820205 is a deficient number, since it is larger than the sum of its proper divisors (7830035).

20820205 is a wasteful number, since it uses less digits than its factorization.

20820205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20820205 is about 4562.9162823791. The cubic root of 20820205 is about 275.1027935275.

It can be divided in two parts, 20820 and 205, that added together give a square (21025 = 145²).

The spelling of 20820205 in words is "twenty million, eight hundred twenty thousand, two hundred five".