21129203 has 8 divisors (see below), whose sum is σ = 22104576. Its totient is φ = 20158600.

The previous prime is 21129191. The next prime is 21129209. The reversal of 21129203 is 30292112.

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

It is a cyclic number.

It is not a de Polignac number, because 21129203 - 2¹² = 21125107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21129209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10358 + ... + 12228.

It is an arithmetic number, because the mean of its divisors is an integer number (2763072).

Almost surely, 2^21129203 is an apocalyptic number.

21129203 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21129203 is a deficient number, since it is larger than the sum of its proper divisors (975373).

21129203 is a wasteful number, since it uses less digits than its factorization.

21129203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2385.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21129203 is about 4596.6512810958. The cubic root of 21129203 is about 276.4570727546.

The spelling of 21129203 in words is "twenty-one million, one hundred twenty-nine thousand, two hundred three".