10212100021 has 4 divisors (see below), whose sum is σ = 10228759852. Its totient is φ = 10195440192.

The previous prime is 10212100007. The next prime is 10212100037. The reversal of 10212100021 is 12000121201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12000121201 = 157 ⋅76433893.

It can be written as a sum of positive squares in 2 ways, for example, as 2306400625 + 7905699396 = 48025^2 + 88914^2 .

It is a cyclic number.

It is not a de Polignac number, because 10212100021 - 2⁷ = 10212099893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10212099980 and 10212100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10212100621) 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, 8328996 + ... + 8330221.

It is an arithmetic number, because the mean of its divisors is an integer number (2557189963).

Almost surely, 2^10212100021 is an apocalyptic number.

It is an amenable number.

10212100021 is a deficient number, since it is larger than the sum of its proper divisors (16659831).

10212100021 is an equidigital number, since it uses as much as digits as its factorization.

10212100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16659830.

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

Adding to 10212100021 its reverse (12000121201), we get a palindrome (22212221222).

The spelling of 10212100021 in words is "ten billion, two hundred twelve million, one hundred thousand, twenty-one".