2100212120221 has 4 divisors (see below), whose sum is σ = 2100232279872. Its totient is φ = 2100191960572.

The previous prime is 2100212120183. The next prime is 2100212120249. The reversal of 2100212120221 is 1220212120012.

It is a happy number.

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 2100212120221 - 2³⁷ = 1962773166749 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2100212120195 and 2100212120204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100212120521) 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, 9922741 + ... + 10132186.

It is an arithmetic number, because the mean of its divisors is an integer number (525058069968).

Almost surely, 2^{2100212120221} is an apocalyptic number.

It is an amenable number.

2100212120221 is a deficient number, since it is larger than the sum of its proper divisors (20159651).

2100212120221 is a wasteful number, since it uses less digits than its factorization.

2100212120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20159650.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2100212120221 its reverse (1220212120012), we get a palindrome (3320424240233).

The spelling of 2100212120221 in words is "two trillion, one hundred billion, two hundred twelve million, one hundred twenty thousand, two hundred twenty-one".