210101100010021 has 4 divisors (see below), whose sum is σ = 229201200010944. Its totient is φ = 191001000009100.

The previous prime is 210101100010019. The next prime is 210101100010049. The reversal of 210101100010021 is 120010001101012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210101100010021 - 2¹ = 210101100010019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210101100010001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9550050000445 + ... + 9550050000466.

It is an arithmetic number, because the mean of its divisors is an integer number (57300300002736).

Almost surely, 2^{210101100010021} is an apocalyptic number.

It is an amenable number.

210101100010021 is a deficient number, since it is larger than the sum of its proper divisors (19100100000923).

210101100010021 is a wasteful number, since it uses less digits than its factorization.

210101100010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19100100000922.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 210101100010021 its reverse (120010001101012), we get a palindrome (330111101111033).

The spelling of 210101100010021 in words is "two hundred ten trillion, one hundred one billion, one hundred million, ten thousand, twenty-one".