20390265 has 32 divisors (see below), whose sum is σ = 41429760. Its totient is φ = 9320832.

The previous prime is 20390263. The next prime is 20390269. The reversal of 20390265 is 56209302.

It is not a de Polignac number, because 20390265 - 2¹ = 20390263 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20390261) 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 31 ways as a sum of consecutive naturals, for example, 9844 + ... + 11733.

It is an arithmetic number, because the mean of its divisors is an integer number (1294680).

Almost surely, 2^20390265 is an apocalyptic number.

It is an amenable number.

20390265 is an abundant number, since it is smaller than the sum of its proper divisors (21039495).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20390265 is a wasteful number, since it uses less digits than its factorization.

20390265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21598 (or 21592 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 20390265 is about 4515.5581050408. The cubic root of 20390265 is about 273.1959708709.

Adding to 20390265 its reverse (56209302), we get a palindrome (76599567).

The spelling of 20390265 in words is "twenty million, three hundred ninety thousand, two hundred sixty-five".