2121111111021 has 16 divisors (see below), whose sum is σ = 3343623427200. Its totient is φ = 1170268198848.

The previous prime is 2121111111019. The next prime is 2121111111029. The reversal of 2121111111021 is 1201111111212.

It is not a de Polignac number, because 2121111111021 - 2¹ = 2121111111019 is a prime.

It is a super-2 number, since 2×2121111111021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121111111029) 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, 1741469926 + ... + 1741471143.

It is an arithmetic number, because the mean of its divisors is an integer number (208976464200).

Almost surely, 2^{2121111111021} is an apocalyptic number.

2121111111021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2121111111021 is a deficient number, since it is larger than the sum of its proper divisors (1222512316179).

2121111111021 is a wasteful number, since it uses less digits than its factorization.

2121111111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3482941108.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 2121111111021 its reverse (1201111111212), we get a palindrome (3322222222233).

The spelling of 2121111111021 in words is "two trillion, one hundred twenty-one billion, one hundred eleven million, one hundred eleven thousand, twenty-one".