20613321 has 6 divisors (see below), whose sum is σ = 29774810. Its totient is φ = 13742208.

The previous prime is 20613301. The next prime is 20613323. The reversal of 20613321 is 12331602.

20613321 is a `hidden beast` number, since 20 + 613 + 32 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20575296 + 38025 = 4536^2 + 195^2 .

It is not a de Polignac number, because 20613321 - 2⁷ = 20613193 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20613294 and 20613303.

It is not an unprimeable number, because it can be changed into a prime (20613323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1145176 + ... + 1145193.

Almost surely, 2^20613321 is an apocalyptic number.

It is an amenable number.

20613321 is a deficient number, since it is larger than the sum of its proper divisors (9161489).

20613321 is a wasteful number, since it uses less digits than its factorization.

20613321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290375 (or 2290372 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 20613321 is about 4540.1895334887. The cubic root of 20613321 is about 274.1885545708.

Adding to 20613321 its reverse (12331602), we get a palindrome (32944923).

The spelling of 20613321 in words is "twenty million, six hundred thirteen thousand, three hundred twenty-one".