221211211002121 has 4 divisors (see below), whose sum is σ = 221211434866500. Its totient is φ = 221210987137744.

The previous prime is 221211211002097. The next prime is 221211211002193. The reversal of 221211211002121 is 121200112112122.

It is a happy number.

221211211002121 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.

It can be written as a sum of positive squares in 2 ways, for example, as 84672920800521 + 136538290201600 = 9201789^2 + 11684960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221211211002121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221211211002721) 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, 110443366 + ... + 112428463.

It is an arithmetic number, because the mean of its divisors is an integer number (55302858716625).

Almost surely, 2^{221211211002121} is an apocalyptic number.

It is an amenable number.

221211211002121 is a deficient number, since it is larger than the sum of its proper divisors (223864379).

221211211002121 is an equidigital number, since it uses as much as digits as its factorization.

221211211002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223864378.

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

Adding to 221211211002121 its reverse (121200112112122), we get a palindrome (342411323114243).

The spelling of 221211211002121 in words is "two hundred twenty-one trillion, two hundred eleven billion, two hundred eleven million, two thousand, one hundred twenty-one".