21221333291 has 24 divisors (see below), whose sum is σ = 22786129440. Its totient is φ = 19758758912.

The previous prime is 21221333269. The next prime is 21221333293. The reversal of 21221333291 is 19233312212.

It is not a de Polignac number, because 21221333291 - 2¹⁰ = 21221332267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221333293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14213141 + ... + 14214633.

It is an arithmetic number, because the mean of its divisors is an integer number (949422060).

Almost surely, 2^21221333291 is an apocalyptic number.

21221333291 is a deficient number, since it is larger than the sum of its proper divisors (1564796149).

21221333291 is a wasteful number, since it uses less digits than its factorization.

21221333291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2023 (or 2006 counting only the distinct ones).

The product of its digits is 3888, while the sum is 29.

The spelling of 21221333291 in words is "twenty-one billion, two hundred twenty-one million, three hundred thirty-three thousand, two hundred ninety-one".