210021010001221 has 4 divisors (see below), whose sum is σ = 210021344743744. Its totient is φ = 210020675258700.

The previous prime is 210021010001141. The next prime is 210021010001267. The reversal of 210021010001221 is 122100010120012.

210021010001221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 210021010001221 - 2²¹ = 210021007904069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021010001281) 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, 166428375 + ... + 167685556.

It is an arithmetic number, because the mean of its divisors is an integer number (52505336185936).

Almost surely, 2^{210021010001221} is an apocalyptic number.

It is an amenable number.

210021010001221 is a deficient number, since it is larger than the sum of its proper divisors (334742523).

210021010001221 is an equidigital number, since it uses as much as digits as its factorization.

210021010001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334742522.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 210021010001221 its reverse (122100010120012), we get a palindrome (332121020121233).

The spelling of 210021010001221 in words is "two hundred ten trillion, twenty-one billion, ten million, one thousand, two hundred twenty-one".