20820065 has 24 divisors (see below), whose sum is σ = 29551680. Its totient is φ = 13793760.

The previous prime is 20820061. The next prime is 20820071. The reversal of 20820065 is 56002802.

It is a happy number.

It is not a de Polignac number, because 20820065 - 2² = 20820061 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20820065.

It is not an unprimeable number, because it can be changed into a prime (20820061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33326 + ... + 33944.

It is an arithmetic number, because the mean of its divisors is an integer number (1231320).

Almost surely, 2^20820065 is an apocalyptic number.

It is an amenable number.

20820065 is a deficient number, since it is larger than the sum of its proper divisors (8731615).

20820065 is an equidigital number, since it uses as much as digits as its factorization.

20820065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 20820065 is about 4562.9009412872. The cubic root of 20820065 is about 275.1021769073.

Adding to 20820065 its reverse (56002802), we get a palindrome (76822867).

The spelling of 20820065 in words is "twenty million, eight hundred twenty thousand, sixty-five".