20820535 has 4 divisors (see below), whose sum is σ = 24984648. Its totient is φ = 16656424.

The previous prime is 20820533. The next prime is 20820539. The reversal of 20820535 is 53502802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20820535 - 2¹ = 20820533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2082049 + ... + 2082058.

It is an arithmetic number, because the mean of its divisors is an integer number (6246162).

Almost surely, 2^20820535 is an apocalyptic number.

20820535 is a deficient number, since it is larger than the sum of its proper divisors (4164113).

20820535 is an equidigital number, since it uses as much as digits as its factorization.

20820535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4164112.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 20820535 is about 4562.9524433200. The cubic root of 20820535 is about 275.1042469784.

The spelling of 20820535 in words is "twenty million, eight hundred twenty thousand, five hundred thirty-five".