21221021211 has 8 divisors (see below), whose sum is σ = 30471210000. Its totient is φ = 13059089952.

The previous prime is 21221021209. The next prime is 21221021251. The reversal of 21221021211 is 11212012212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21221021211 - 2¹ = 21221021209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221021251) 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 7 ways as a sum of consecutive naturals, for example, 272064336 + ... + 272064413.

It is an arithmetic number, because the mean of its divisors is an integer number (3808901250).

Almost surely, 2^21221021211 is an apocalyptic number.

21221021211 is a deficient number, since it is larger than the sum of its proper divisors (9250188789).

21221021211 is a wasteful number, since it uses less digits than its factorization.

21221021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544128765.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221021211 its reverse (11212012212), we get a palindrome (32433033423).

The spelling of 21221021211 in words is "twenty-one billion, two hundred twenty-one million, twenty-one thousand, two hundred eleven".