212021111110021 has 4 divisors (see below), whose sum is σ = 212050024401292. Its totient is φ = 211992197818752.

The previous prime is 212021111109991. The next prime is 212021111110097. The reversal of 212021111110021 is 120011111120212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30181684613796 + 181839426496225 = 5493786^2 + 13484785^2 .

It is a cyclic number.

It is not a de Polignac number, because 212021111110021 - 2¹⁷ = 212021110978949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212021111109977 and 212021111110004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212021111110121) 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, 14456634636 + ... + 14456649301.

It is an arithmetic number, because the mean of its divisors is an integer number (53012506100323).

Almost surely, 2^{212021111110021} is an apocalyptic number.

It is an amenable number.

212021111110021 is a deficient number, since it is larger than the sum of its proper divisors (28913291271).

212021111110021 is an equidigital number, since it uses as much as digits as its factorization.

212021111110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28913291270.

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

Adding to 212021111110021 its reverse (120011111120212), we get a palindrome (332032222230233).

The spelling of 212021111110021 in words is "two hundred twelve trillion, twenty-one billion, one hundred eleven million, one hundred ten thousand, twenty-one".