20653205 has 4 divisors (see below), whose sum is σ = 24783852. Its totient is φ = 16522560.

The previous prime is 20653189. The next prime is 20653229. The reversal of 20653205 is 50235602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50235602 = 2 ⋅25117801.

It can be written as a sum of positive squares in 2 ways, for example, as 10355524 + 10297681 = 3218^2 + 3209^2 .

It is not a de Polignac number, because 20653205 - 2⁴ = 20653189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2065316 + ... + 2065325.

It is an arithmetic number, because the mean of its divisors is an integer number (6195963).

Almost surely, 2^20653205 is an apocalyptic number.

It is an amenable number.

20653205 is a deficient number, since it is larger than the sum of its proper divisors (4130647).

20653205 is an equidigital number, since it uses as much as digits as its factorization.

20653205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4130646.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 20653205 is about 4544.5797385457. The cubic root of 20653205 is about 274.3652799486.

Adding to 20653205 its reverse (50235602), we get a palindrome (70888807).

The spelling of 20653205 in words is "twenty million, six hundred fifty-three thousand, two hundred five".