21211112012021 has 4 divisors (see below), whose sum is σ = 21215049480192. Its totient is φ = 21207174543852.

The previous prime is 21211112012009. The next prime is 21211112012107. The reversal of 21211112012021 is 12021021111212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211112012021 is a prime.

It is a super-2 number, since 2×21211112012021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211112012521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1968726005 + ... + 1968736778.

It is an arithmetic number, because the mean of its divisors is an integer number (5303762370048).

Almost surely, 2^{21211112012021} is an apocalyptic number.

It is an amenable number.

21211112012021 is a deficient number, since it is larger than the sum of its proper divisors (3937468171).

21211112012021 is an equidigital number, since it uses as much as digits as its factorization.

21211112012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3937468170.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21211112012021 its reverse (12021021111212), we get a palindrome (33232133123233).

The spelling of 21211112012021 in words is "twenty-one trillion, two hundred eleven billion, one hundred twelve million, twelve thousand, twenty-one".