21220333333 has 4 divisors (see below), whose sum is σ = 21221327628. Its totient is φ = 21219339040.

The previous prime is 21220333327. The next prime is 21220333339. The reversal of 21220333333 is 33333302212.

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

It is an interprime number because it is at equal distance from previous prime (21220333327) and next prime (21220333339).

It can be written as a sum of positive squares in 2 ways, for example, as 5420346129 + 15799987204 = 73623^2 + 125698^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220333333 - 2²¹ = 21218236181 is a prime.

It is a Duffinian number.

21220333333 is a modest number, since divided by 333333 gives 21220 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21220333298 and 21220333307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220333339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 464416 + ... + 508057.

It is an arithmetic number, because the mean of its divisors is an integer number (5305331907).

Almost surely, 2^21220333333 is an apocalyptic number.

It is an amenable number.

21220333333 is a deficient number, since it is larger than the sum of its proper divisors (994295).

21220333333 is an equidigital number, since it uses as much as digits as its factorization.

21220333333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994294.

The product of its (nonzero) digits is 5832, while the sum is 25.

Adding to 21220333333 its reverse (33333302212), we get a palindrome (54553635545).

The spelling of 21220333333 in words is "twenty-one billion, two hundred twenty million, three hundred thirty-three thousand, three hundred thirty-three".