21221300333 has 12 divisors (see below), whose sum is σ = 21987757428. Its totient is φ = 20480718720.

The previous prime is 21221300323. The next prime is 21221300369. The reversal of 21221300333 is 33300312212.

It can be written as a sum of positive squares in 6 ways, for example, as 6219215044 + 15002085289 = 78862^2 + 122483^2 .

It is not a de Polignac number, because 21221300333 - 2²⁶ = 21154191469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221300323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2832953 + ... + 2840433.

It is an arithmetic number, because the mean of its divisors is an integer number (1832313119).

Almost surely, 2^21221300333 is an apocalyptic number.

It is an amenable number.

21221300333 is a deficient number, since it is larger than the sum of its proper divisors (766457095).

21221300333 is an equidigital number, since it uses as much as digits as its factorization.

21221300333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10912 (or 10883 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21221300333 its reverse (33300312212), we get a palindrome (54521612545).

The spelling of 21221300333 in words is "twenty-one billion, two hundred twenty-one million, three hundred thousand, three hundred thirty-three".