20765903 has 4 divisors (see below), whose sum is σ = 20971608. Its totient is φ = 20560200.

The previous prime is 20765893. The next prime is 20765909. The reversal of 20765903 is 30956702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20765903 - 2¹⁰ = 20764879 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20765903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20765909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102701 + ... + 102902.

It is an arithmetic number, because the mean of its divisors is an integer number (5242902).

Almost surely, 2^20765903 is an apocalyptic number.

20765903 is a deficient number, since it is larger than the sum of its proper divisors (205705).

20765903 is a wasteful number, since it uses less digits than its factorization.

20765903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205704.

The product of its (nonzero) digits is 11340, while the sum is 32.

The square root of 20765903 is about 4556.9620362693. The cubic root of 20765903 is about 274.8634164722.

The spelling of 20765903 in words is "twenty million, seven hundred sixty-five thousand, nine hundred three".