21220303 has 8 divisors (see below), whose sum is σ = 23034368. Its totient is φ = 19432224.

The previous prime is 21220261. The next prime is 21220313. The reversal of 21220303 is 30302212.

It is a happy number.

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 21220303 - 2¹³ = 21212111 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220313) 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, 4776 + ... + 8077.

It is an arithmetic number, because the mean of its divisors is an integer number (2879296).

Almost surely, 2^21220303 is an apocalyptic number.

21220303 is a deficient number, since it is larger than the sum of its proper divisors (1814065).

21220303 is a wasteful number, since it uses less digits than its factorization.

21220303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12993.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 21220303 is about 4606.5500105828. The cubic root of 21220303 is about 276.8538242684.

Adding to 21220303 its reverse (30302212), we get a palindrome (51522515).

The spelling of 21220303 in words is "twenty-one million, two hundred twenty thousand, three hundred three".