210010100100021 has 24 divisors (see below), whose sum is σ = 343876187301920. Its totient is φ = 122435038113696.

The previous prime is 210010100100007. The next prime is 210010100100041. The reversal of 210010100100021 is 120001001010012.

It is a happy number.

It is not a de Polignac number, because 210010100100021 - 2¹³ = 210010100091829 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 210010100099976 and 210010100100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210010100100041) 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, 47235737791 + ... + 47235742236.

Almost surely, 2^{210010100100021} is an apocalyptic number.

It is an amenable number.

210010100100021 is a deficient number, since it is larger than the sum of its proper divisors (133866087201899).

210010100100021 is a wasteful number, since it uses less digits than its factorization.

210010100100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94471480065 (or 94471480062 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 210010100100021 its reverse (120001001010012), we get a palindrome (330011101110033).

Subtracting from 210010100100021 its reverse (120001001010012), we obtain a palindrome (90009099090009).

The spelling of 210010100100021 in words is "two hundred ten trillion, ten billion, one hundred million, one hundred thousand, twenty-one".