213303503 has 4 divisors (see below), whose sum is σ = 243775440. Its totient is φ = 182831568.

The previous prime is 213303491. The next prime is 213303509. The reversal of 213303503 is 305303312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 213303503 - 2¹⁸ = 213041359 is a prime.

It is a super-3 number, since 3×213303503³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213303509) 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, 15235958 + ... + 15235971.

It is an arithmetic number, because the mean of its divisors is an integer number (60943860).

Almost surely, 2^213303503 is an apocalyptic number.

213303503 is a deficient number, since it is larger than the sum of its proper divisors (30471937).

213303503 is an equidigital number, since it uses as much as digits as its factorization.

213303503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30471936.

The product of its (nonzero) digits is 810, while the sum is 20.

The square root of 213303503 is about 14604.9136594504. The cubic root of 213303503 is about 597.4927812016.

Adding to 213303503 its reverse (305303312), we get a palindrome (518606815).

The spelling of 213303503 in words is "two hundred thirteen million, three hundred three thousand, five hundred three".