21330331221 has 32 divisors (see below), whose sum is σ = 29764094976. Its totient is φ = 13575744000.

The previous prime is 21330331201. The next prime is 21330331369. The reversal of 21330331221 is 12213303312.

It is not a de Polignac number, because 21330331221 - 2⁵ = 21330331189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330331201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1470876 + ... + 1485306.

It is an arithmetic number, because the mean of its divisors is an integer number (930127968).

Almost surely, 2^21330331221 is an apocalyptic number.

It is an amenable number.

21330331221 is a deficient number, since it is larger than the sum of its proper divisors (8433763755).

21330331221 is a wasteful number, since it uses less digits than its factorization.

21330331221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14733.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21330331221 its reverse (12213303312), we get a palindrome (33543634533).

The spelling of 21330331221 in words is "twenty-one billion, three hundred thirty million, three hundred thirty-one thousand, two hundred twenty-one".