2100012122221 has 8 divisors (see below), whose sum is σ = 2265014850840. Its totient is φ = 1935504155712.

The previous prime is 2100012122209. The next prime is 2100012122267. The reversal of 2100012122221 is 1222212100012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 156134829321 + 1943877292900 = 395139^2 + 1394230^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2100012122221 - 2⁵ = 2100012122189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2100012122195 and 2100012122204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100012122281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123681706 + ... + 123698683.

It is an arithmetic number, because the mean of its divisors is an integer number (283126856355).

Almost surely, 2^{2100012122221} is an apocalyptic number.

It is an amenable number.

2100012122221 is a deficient number, since it is larger than the sum of its proper divisors (165002728619).

2100012122221 is a wasteful number, since it uses less digits than its factorization.

2100012122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247381055.

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

Adding to 2100012122221 its reverse (1222212100012), we get a palindrome (3322224222233).

It can be divided in two parts, 2100012 and 122221, that multiplied together give a palindrome (256665566652).

The spelling of 2100012122221 in words is "two trillion, one hundred billion, twelve million, one hundred twenty-two thousand, two hundred twenty-one".