212021210021 has 4 divisors (see below), whose sum is σ = 212846195532. Its totient is φ = 211196224512.

The previous prime is 212021209991. The next prime is 212021210033. The reversal of 212021210021 is 120012120212.

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 133557357025 + 78463852996 = 365455^2 + 280114^2 .

It is a cyclic number.

It is not a de Polignac number, because 212021210021 - 2³⁰ = 210947468197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212021209978 and 212021210005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212021213021) 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, 412492370 + ... + 412492883.

It is an arithmetic number, because the mean of its divisors is an integer number (53211548883).

Almost surely, 2^212021210021 is an apocalyptic number.

It is an amenable number.

212021210021 is a deficient number, since it is larger than the sum of its proper divisors (824985511).

212021210021 is an equidigital number, since it uses as much as digits as its factorization.

212021210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824985510.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 212021210021 its reverse (120012120212), we get a palindrome (332033330233).

The spelling of 212021210021 in words is "two hundred twelve billion, twenty-one million, two hundred ten thousand, twenty-one".