21032003 has 2 divisors, whose sum is σ = 21032004. Its totient is φ = 21032002.

The previous prime is 21031979. The next prime is 21032023. The reversal of 21032003 is 30023012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21032003 - 2¹⁰ = 21030979 is a prime.

It is not a weakly prime, because it can be changed into another prime (21032023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10516001 + 10516002.

It is an arithmetic number, because the mean of its divisors is an integer number (10516002).

Almost surely, 2^21032003 is an apocalyptic number.

21032003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21032003 is an equidigital number, since it uses as much as digits as its factorization.

21032003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 11.

The square root of 21032003 is about 4586.0661791998. The cubic root of 21032003 is about 276.0324954738.

Adding to 21032003 its reverse (30023012), we get a palindrome (51055015).

The spelling of 21032003 in words is "twenty-one million, thirty-two thousand, three".