212012121110021 has 4 divisors (see below), whose sum is σ = 212129840224044. Its totient is φ = 211894401996000.

The previous prime is 212012121109993. The next prime is 212012121110033. The reversal of 212012121110021 is 120011121210212.

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 124939054732996 + 87073066377025 = 11177614^2 + 9331295^2 .

It is a cyclic number.

It is not a de Polignac number, because 212012121110021 - 2²⁶ = 212012054001157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212012121112021) 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, 58859554310 + ... + 58859557911.

It is an arithmetic number, because the mean of its divisors is an integer number (53032460056011).

Almost surely, 2^{212012121110021} is an apocalyptic number.

It is an amenable number.

212012121110021 is a deficient number, since it is larger than the sum of its proper divisors (117719114023).

212012121110021 is a wasteful number, since it uses less digits than its factorization.

212012121110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117719114022.

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

Adding to 212012121110021 its reverse (120011121210212), we get a palindrome (332023242320233).

The spelling of 212012121110021 in words is "two hundred twelve trillion, twelve billion, one hundred twenty-one million, one hundred ten thousand, twenty-one".