20503665 has 64 divisors (see below), whose sum is σ = 44889600. Its totient is φ = 8646912.

The previous prime is 20503627. The next prime is 20503673. The reversal of 20503665 is 56630502.

It is not a de Polignac number, because 20503665 - 2⁶ = 20503601 is a prime.

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

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 11451 + ... + 13119.

It is an arithmetic number, because the mean of its divisors is an integer number (701400).

Almost surely, 2^20503665 is an apocalyptic number.

It is an amenable number.

20503665 is an abundant number, since it is smaller than the sum of its proper divisors (24385935).

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

20503665 is a wasteful number, since it uses less digits than its factorization.

20503665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1703 (or 1697 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 20503665 is about 4528.0972825239. The cubic root of 20503665 is about 273.7014926249.

The spelling of 20503665 in words is "twenty million, five hundred three thousand, six hundred sixty-five".