210221210000021 has 24 divisors (see below), whose sum is σ = 244674047566872. Its totient is φ = 179859501747200.

The previous prime is 210221209999963. The next prime is 210221210000027. The reversal of 210221210000021 is 120000012122012.

It can be written as a sum of positive squares in 4 ways, for example, as 42905303445796 + 167315906554225 = 6550214^2 + 12935065^2 .

It is not a de Polignac number, because 210221210000021 - 2³⁴ = 210204030130837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210221209999960 and 210221210000005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210221210000027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39154841 + ... + 44198913.

It is an arithmetic number, because the mean of its divisors is an integer number (10194751981953).

Almost surely, 2^{210221210000021} is an apocalyptic number.

It is an amenable number.

210221210000021 is a deficient number, since it is larger than the sum of its proper divisors (34452837566851).

210221210000021 is a wasteful number, since it uses less digits than its factorization.

210221210000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5064373 (or 5064362 counting only the distinct ones).

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

Adding to 210221210000021 its reverse (120000012122012), we get a palindrome (330221222122033).

The spelling of 210221210000021 in words is "two hundred ten trillion, two hundred twenty-one billion, two hundred ten million, twenty-one", and thus it is an aban number.