212010100021 has 4 divisors (see below), whose sum is σ = 212013107500. Its totient is φ = 212007092544.

The previous prime is 212010100007. The next prime is 212010100063. The reversal of 212010100021 is 120001010212.

212010100021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 126035650225 + 85974449796 = 355015^2 + 293214^2 .

It is a cyclic number.

It is not a de Polignac number, because 212010100021 - 2¹⁷ = 212009968949 is a prime.

It is a super-3 number, since 3×212010100021³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212010099980 and 212010100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212010100121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1395396 + ... + 1539853.

It is an arithmetic number, because the mean of its divisors is an integer number (53003276875).

Almost surely, 2^212010100021 is an apocalyptic number.

It is an amenable number.

212010100021 is a deficient number, since it is larger than the sum of its proper divisors (3007479).

212010100021 is an equidigital number, since it uses as much as digits as its factorization.

212010100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3007478.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 212010100021 its reverse (120001010212), we get a palindrome (332011110233).

The spelling of 212010100021 in words is "two hundred twelve billion, ten million, one hundred thousand, twenty-one".