20571265 has 16 divisors (see below), whose sum is σ = 29002176. Its totient is φ = 13809600.

The previous prime is 20571253. The next prime is 20571283. The reversal of 20571265 is 56217502.

It is not a de Polignac number, because 20571265 - 2⁷ = 20571137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 13671 + ... + 15100.

It is an arithmetic number, because the mean of its divisors is an integer number (1812636).

Almost surely, 2^20571265 is an apocalyptic number.

It is an amenable number.

20571265 is a deficient number, since it is larger than the sum of its proper divisors (8430911).

20571265 is a wasteful number, since it uses less digits than its factorization.

20571265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28800.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 20571265 is about 4535.5556440198. Note that the first 3 decimals coincide. The cubic root of 20571265 is about 274.0019580019.

Adding to 20571265 its reverse (56217502), we get a palindrome (76788767).

The spelling of 20571265 in words is "twenty million, five hundred seventy-one thousand, two hundred sixty-five".