20531265 has 16 divisors (see below), whose sum is σ = 32973696. Its totient is φ = 10908800.

The previous prime is 20531243. The next prime is 20531297. The reversal of 20531265 is 56213502.

It is not a de Polignac number, because 20531265 - 2¹⁶ = 20465729 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1780 + ... + 6650.

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

Almost surely, 2^20531265 is an apocalyptic number.

It is an amenable number.

20531265 is a deficient number, since it is larger than the sum of its proper divisors (12442431).

20531265 is a wasteful number, since it uses less digits than its factorization.

20531265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5160.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 20531265 is about 4531.1438953094. The cubic root of 20531265 is about 273.8242474946.

Adding to 20531265 its reverse (56213502), we get a palindrome (76744767).

The spelling of 20531265 in words is "twenty million, five hundred thirty-one thousand, two hundred sixty-five".