21210000210001 has 4 divisors (see below), whose sum is σ = 21210104430900. Its totient is φ = 21209895989104.

The previous prime is 21210000209921. The next prime is 21210000210037. The reversal of 21210000210001 is 10001200001212.

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 7028569811025 + 14181430398976 = 2651145^2 + 3765824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210000210001 - 2¹¹ = 21210000207953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21210000210001.

It is not an unprimeable number, because it can be changed into a prime (21210000210601) 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, 51804586 + ... + 52212403.

It is an arithmetic number, because the mean of its divisors is an integer number (5302526107725).

Almost surely, 2^{21210000210001} is an apocalyptic number.

It is an amenable number.

21210000210001 is a deficient number, since it is larger than the sum of its proper divisors (104220899).

21210000210001 is a wasteful number, since it uses less digits than its factorization.

21210000210001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104220898.

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

Adding to 21210000210001 its reverse (10001200001212), we get a palindrome (31211200211213).

The spelling of 21210000210001 in words is "twenty-one trillion, two hundred ten billion, two hundred ten thousand, one".