221012002121 has 4 divisors (see below), whose sum is σ = 221012950992. Its totient is φ = 221011053252.

The previous prime is 221012002087. The next prime is 221012002151. The reversal of 221012002121 is 121200210122.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 121200210122 = 2 ⋅60600105061.

It is a cyclic number.

It is not a de Polignac number, because 221012002121 - 2¹⁴ = 221011985737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221012002096 and 221012002105.

It is not an unprimeable number, because it can be changed into a prime (221012002151) 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, 141446 + ... + 679728.

It is an arithmetic number, because the mean of its divisors is an integer number (55253237748).

Almost surely, 2^221012002121 is an apocalyptic number.

It is an amenable number.

221012002121 is a deficient number, since it is larger than the sum of its proper divisors (948871).

221012002121 is an equidigital number, since it uses as much as digits as its factorization.

221012002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948870.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221012002121 its reverse (121200210122), we get a palindrome (342212212243).

The spelling of 221012002121 in words is "two hundred twenty-one billion, twelve million, two thousand, one hundred twenty-one".