21121331211 has 12 divisors (see below), whose sum is σ = 30509851320. Its totient is φ = 14080305120.

The previous prime is 21121331201. The next prime is 21121331263. The reversal of 21121331211 is 11213312112.

21121331211 is a `hidden beast` number, since 2 + 1 + 121 + 331 + 211 = 666.

It is not a de Polignac number, because 21121331211 - 2¹⁰ = 21121330187 is a prime.

It is a super-2 number, since 2×21121331211² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121331201) 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 11 ways as a sum of consecutive naturals, for example, 385060 + ... + 436478.

It is an arithmetic number, because the mean of its divisors is an integer number (2542487610).

Almost surely, 2^21121331211 is an apocalyptic number.

21121331211 is a deficient number, since it is larger than the sum of its proper divisors (9388520109).

21121331211 is a wasteful number, since it uses less digits than its factorization.

21121331211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97066 (or 97063 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21121331211 its reverse (11213312112), we get a palindrome (32334643323).

It can be divided in two parts, 2 and 1121331211, that multiplied together give a palindrome (2242662422).

The spelling of 21121331211 in words is "twenty-one billion, one hundred twenty-one million, three hundred thirty-one thousand, two hundred eleven".