20928503 has 4 divisors (see below), whose sum is σ = 21603648. Its totient is φ = 20253360.

The previous prime is 20928499. The next prime is 20928511. The reversal of 20928503 is 30582902.

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 20928503 - 2² = 20928499 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20928703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 337526 + ... + 337587.

It is an arithmetic number, because the mean of its divisors is an integer number (5400912).

Almost surely, 2^20928503 is an apocalyptic number.

20928503 is a deficient number, since it is larger than the sum of its proper divisors (675145).

20928503 is an equidigital number, since it uses as much as digits as its factorization.

20928503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675144.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 20928503 is about 4574.7680815534. The cubic root of 20928503 is about 275.5789587724.

The spelling of 20928503 in words is "twenty million, nine hundred twenty-eight thousand, five hundred three".