21121201211 has 16 divisors (see below), whose sum is σ = 24259305600. Its totient is φ = 18186537600.

The previous prime is 21121201187. The next prime is 21121201229. The reversal of 21121201211 is 11210212112.

It is not a de Polignac number, because 21121201211 - 2¹⁰ = 21121200187 is a prime.

It is a super-2 number, since 2×21121201211² (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 (21121201711) 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, 1348835 + ... + 1364403.

It is an arithmetic number, because the mean of its divisors is an integer number (1516206600).

Almost surely, 2^21121201211 is an apocalyptic number.

21121201211 is a deficient number, since it is larger than the sum of its proper divisors (3138104389).

21121201211 is a wasteful number, since it uses less digits than its factorization.

21121201211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22090.

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

Adding to 21121201211 its reverse (11210212112), we get a palindrome (32331413323).

The spelling of 21121201211 in words is "twenty-one billion, one hundred twenty-one million, two hundred one thousand, two hundred eleven".