211210100021 has 6 divisors (see below), whose sum is σ = 220792411350. Its totient is φ = 202027051688.

The previous prime is 211210099979. The next prime is 211210100029. The reversal of 211210100021 is 120001012112.

211210100021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 148151859025 + 63058240996 = 384905^2 + 251114^2 .

It is a de Polignac number, because none of the positive numbers 2^k-211210100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211210099975 and 211210100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211210100029) 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 5 ways as a sum of consecutive naturals, for example, 199630946 + ... + 199632003.

It is an arithmetic number, because the mean of its divisors is an integer number (36798735225).

Almost surely, 2^211210100021 is an apocalyptic number.

It is an amenable number.

211210100021 is a deficient number, since it is larger than the sum of its proper divisors (9582311329).

211210100021 is an equidigital number, since it uses as much as digits as its factorization.

211210100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399262995 (or 399262972 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 211210100021 its reverse (120001012112), we get a palindrome (331211112133).

The spelling of 211210100021 in words is "two hundred eleven billion, two hundred ten million, one hundred thousand, twenty-one".