20671265 has 16 divisors (see below), whose sum is σ = 25775616. Its totient is φ = 15897600.

The previous prime is 20671249. The next prime is 20671267. The reversal of 20671265 is 56217602.

It is not a de Polignac number, because 20671265 - 2⁴ = 20671249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20671267) 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, 29570 + ... + 30260.

It is an arithmetic number, because the mean of its divisors is an integer number (1610976).

Almost surely, 2^20671265 is an apocalyptic number.

It is an amenable number.

20671265 is a deficient number, since it is larger than the sum of its proper divisors (5104351).

20671265 is a wasteful number, since it uses less digits than its factorization.

20671265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20671265 is about 4546.5662867707. The cubic root of 20671265 is about 274.4452286920.

Adding to 20671265 its reverse (56217602), we get a palindrome (76888867).

The spelling of 20671265 in words is "twenty million, six hundred seventy-one thousand, two hundred sixty-five".