21211212011 has 8 divisors (see below), whose sum is σ = 23156373744. Its totient is φ = 19268861920.

The previous prime is 21211211969. The next prime is 21211212017. The reversal of 21211212011 is 11021211212.

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

It is a de Polignac number, because none of the positive numbers 2^k-21211212011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211212017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 687116 + ... + 717321.

It is an arithmetic number, because the mean of its divisors is an integer number (2894546718).

Almost surely, 2^21211212011 is an apocalyptic number.

21211212011 is a deficient number, since it is larger than the sum of its proper divisors (1945161733).

21211212011 is a wasteful number, since it uses less digits than its factorization.

21211212011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1405821.

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

Adding to 21211212011 its reverse (11021211212), we get a palindrome (32232423223).

The spelling of 21211212011 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, eleven".