21092003 has 4 divisors (see below), whose sum is σ = 21104040. Its totient is φ = 21079968.

The previous prime is 21091991. The next prime is 21092011. The reversal of 21092003 is 30029012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21092003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21092063) 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, 2825 + ... + 7082.

It is an arithmetic number, because the mean of its divisors is an integer number (5276010).

Almost surely, 2^21092003 is an apocalyptic number.

21092003 is a deficient number, since it is larger than the sum of its proper divisors (12037).

21092003 is an equidigital number, since it uses as much as digits as its factorization.

21092003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12036.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21092003 is about 4592.6030745101. The cubic root of 21092003 is about 276.2947343320.

The spelling of 21092003 in words is "twenty-one million, ninety-two thousand, three".