20919903 has 8 divisors (see below), whose sum is σ = 29106048. Its totient is φ = 13340184.

The previous prime is 20919883. The next prime is 20919919. The reversal of 20919903 is 30991902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-20919903 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20919953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151525 + ... + 151662.

It is an arithmetic number, because the mean of its divisors is an integer number (3638256).

Almost surely, 2^20919903 is an apocalyptic number.

20919903 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20919903 is a deficient number, since it is larger than the sum of its proper divisors (8186145).

20919903 is a wasteful number, since it uses less digits than its factorization.

20919903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303213.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 20919903 is about 4573.8280466148. The cubic root of 20919903 is about 275.5412063709.

The spelling of 20919903 in words is "twenty million, nine hundred nineteen thousand, nine hundred three".