210001221001221 has 16 divisors (see below), whose sum is σ = 301542456836544. Its totient is φ = 129230559730944.

The previous prime is 210001221001199. The next prime is 210001221001223. The reversal of 210001221001221 is 122100122100012.

210001221001221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 210001221001221 - 2²⁶ = 210001153892357 is a prime.

210001221001221 is a modest number, since divided by 1221001221 gives 210 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 210001221001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210001221001223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14688036 + ... + 25213901.

It is an arithmetic number, because the mean of its divisors is an integer number (18846403552284).

Almost surely, 2^{210001221001221} is an apocalyptic number.

It is an amenable number.

210001221001221 is a deficient number, since it is larger than the sum of its proper divisors (91541235835323).

210001221001221 is a wasteful number, since it uses less digits than its factorization.

210001221001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40036900.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 210001221001221 its reverse (122100122100012), we get a palindrome (332101343101233).

The spelling of 210001221001221 in words is "two hundred ten trillion, one billion, two hundred twenty-one million, one thousand, two hundred twenty-one".