210221112012121 has 4 divisors (see below), whose sum is σ = 240252699442432. Its totient is φ = 180189524581812.

The previous prime is 210221112012091. The next prime is 210221112012143. The reversal of 210221112012121 is 121210211122012.

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 210221112012121 - 2¹⁹ = 210221111487833 is a prime.

It is a super-2 number, since 2×210221112012121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210221112012421) 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, 15015793715145 + ... + 15015793715158.

It is an arithmetic number, because the mean of its divisors is an integer number (60063174860608).

Almost surely, 2^{210221112012121} is an apocalyptic number.

It is an amenable number.

210221112012121 is a deficient number, since it is larger than the sum of its proper divisors (30031587430311).

210221112012121 is an equidigital number, since it uses as much as digits as its factorization.

210221112012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30031587430310.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 210221112012121 its reverse (121210211122012), we get a palindrome (331431323134133).

The spelling of 210221112012121 in words is "two hundred ten trillion, two hundred twenty-one billion, one hundred twelve million, twelve thousand, one hundred twenty-one".