21233503 has 2 divisors, whose sum is σ = 21233504. Its totient is φ = 21233502.

The previous prime is 21233497. The next prime is 21233579. The reversal of 21233503 is 30533212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21233503 - 2¹³ = 21225311 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21233593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616751 + 10616752.

It is an arithmetic number, because the mean of its divisors is an integer number (10616752).

Almost surely, 2^21233503 is an apocalyptic number.

21233503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233503 is an equidigital number, since it uses as much as digits as its factorization.

21233503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 19.

The square root of 21233503 is about 4607.9825303488. The cubic root of 21233503 is about 276.9112176209.

Adding to 21233503 its reverse (30533212), we get a palindrome (51766715).

It can be divided in two parts, 21233 and 503, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 21233503 in words is "twenty-one million, two hundred thirty-three thousand, five hundred three".