21221231011 has 2 divisors, whose sum is σ = 21221231012. Its totient is φ = 21221231010.

The previous prime is 21221230949. The next prime is 21221231021. The reversal of 21221231011 is 11013212212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21221231011 - 2¹³ = 21221222819 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221231021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610615505 + 10610615506.

It is an arithmetic number, because the mean of its divisors is an integer number (10610615506).

Almost surely, 2^21221231011 is an apocalyptic number.

21221231011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221231011 is an equidigital number, since it uses as much as digits as its factorization.

21221231011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21221231011 its reverse (11013212212), we get a palindrome (32234443223).

The spelling of 21221231011 in words is "twenty-one billion, two hundred twenty-one million, two hundred thirty-one thousand, eleven".