21120331211 has 16 divisors (see below), whose sum is σ = 24375389184. Its totient is φ = 17924912064.

The previous prime is 21120331171. The next prime is 21120331223. The reversal of 21120331211 is 11213302112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21120331211 is a prime.

It is a super-3 number, since 3×21120331211³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21120331211.

It is not an unprimeable number, because it can be changed into a prime (21120331241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1778951 + ... + 1790783.

It is an arithmetic number, because the mean of its divisors is an integer number (1523461824).

Almost surely, 2^21120331211 is an apocalyptic number.

21120331211 is a deficient number, since it is larger than the sum of its proper divisors (3255057973).

21120331211 is a wasteful number, since it uses less digits than its factorization.

21120331211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14330.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21120331211 its reverse (11213302112), we get a palindrome (32333633323).

The spelling of 21120331211 in words is "twenty-one billion, one hundred twenty million, three hundred thirty-one thousand, two hundred eleven".