21121100211 has 32 divisors (see below), whose sum is σ = 29021124352. Its totient is φ = 13655900160.

The previous prime is 21121100173. The next prime is 21121100227. The reversal of 21121100211 is 11200112112.

It is not a de Polignac number, because 21121100211 - 2⁷ = 21121100083 is a prime.

It is a super-2 number, since 2×21121100211² (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 (21121100251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18317811 + ... + 18318963.

It is an arithmetic number, because the mean of its divisors is an integer number (906910136).

Almost surely, 2^21121100211 is an apocalyptic number.

21121100211 is a deficient number, since it is larger than the sum of its proper divisors (7900024141).

21121100211 is a wasteful number, since it uses less digits than its factorization.

21121100211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2083.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21121100211 its reverse (11200112112), we get a palindrome (32321212323).

The spelling of 21121100211 in words is "twenty-one billion, one hundred twenty-one million, one hundred thousand, two hundred eleven".