21102121211 has 8 divisors (see below), whose sum is σ = 21494415120. Its totient is φ = 20712102048.

The previous prime is 21102121153. The next prime is 21102121217. The reversal of 21102121211 is 11212120112.

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

It is a cyclic number.

It is not a de Polignac number, because 21102121211 - 2¹⁰ = 21102120187 is a prime.

It is a super-2 number, since 2×21102121211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102121217) 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, 549956 + ... + 587073.

It is an arithmetic number, because the mean of its divisors is an integer number (2686801890).

Almost surely, 2^21102121211 is an apocalyptic number.

21102121211 is a deficient number, since it is larger than the sum of its proper divisors (392293909).

21102121211 is a wasteful number, since it uses less digits than its factorization.

21102121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137373.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21102121211 its reverse (11212120112), we get a palindrome (32314241323).

It can be divided in two parts, 211021 and 21211, that added together give a palindrome (232232).

The spelling of 21102121211 in words is "twenty-one billion, one hundred two million, one hundred twenty-one thousand, two hundred eleven".