210021210111221 has 8 divisors (see below), whose sum is σ = 213465095823000. Its totient is φ = 206577353917440.

The previous prime is 210021210111161. The next prime is 210021210111347. The reversal of 210021210111221 is 122111012120012.

It can be written as a sum of positive squares in 4 ways, for example, as 1706978832196 + 208314231279025 = 1306514^2 + 14433095^2 .

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 210021210111221 - 2¹⁰ = 210021210110197 is a prime.

It is a super-2 number, since 2×210021210111221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 210021210111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021200111221) 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, 7201505 + ... + 21723353.

It is an arithmetic number, because the mean of its divisors is an integer number (26683136977875).

Almost surely, 2^{210021210111221} is an apocalyptic number.

It is an amenable number.

210021210111221 is a deficient number, since it is larger than the sum of its proper divisors (3443885711779).

210021210111221 is a wasteful number, since it uses less digits than its factorization.

210021210111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14758999.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 210021210111221 its reverse (122111012120012), we get a palindrome (332132222231233).

The spelling of 210021210111221 in words is "two hundred ten trillion, twenty-one billion, two hundred ten million, one hundred eleven thousand, two hundred twenty-one".