20321265 has 16 divisors (see below), whose sum is σ = 32973696. Its totient is φ = 10684800.

The previous prime is 20321263. The next prime is 20321269. The reversal of 20321265 is 56212302.

It is not a de Polignac number, because 20321265 - 2¹ = 20321263 is a prime.

It is a super-2 number, since 2×20321265² = 825907622400450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20321261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8476 + ... + 10605.

It is an arithmetic number, because the mean of its divisors is an integer number (2060856).

Almost surely, 2^20321265 is an apocalyptic number.

It is an amenable number.

20321265 is a deficient number, since it is larger than the sum of its proper divisors (12652431).

20321265 is a wasteful number, since it uses less digits than its factorization.

20321265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19160.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20321265 is about 4507.9113788982. The cubic root of 20321265 is about 272.8874604904.

Adding to 20321265 its reverse (56212302), we get a palindrome (76533567).

The spelling of 20321265 in words is "twenty million, three hundred twenty-one thousand, two hundred sixty-five".