221002302121 has 4 divisors (see below), whose sum is σ = 225172156932. Its totient is φ = 216832447312.

The previous prime is 221002302113. The next prime is 221002302133. The reversal of 221002302121 is 121203200122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121203200122 = 2 ⋅60601600061.

It can be written as a sum of positive squares in 2 ways, for example, as 75521085721 + 145481216400 = 274811^2 + 381420^2 .

It is a cyclic number.

It is not a de Polignac number, because 221002302121 - 2³ = 221002302113 is a prime.

It is a super-2 number, since 2×221002302121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221002302095 and 221002302104.

It is not an unprimeable number, because it can be changed into a prime (221002302161) 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, 2084927326 + ... + 2084927431.

It is an arithmetic number, because the mean of its divisors is an integer number (56293039233).

Almost surely, 2^221002302121 is an apocalyptic number.

It is an amenable number.

221002302121 is a deficient number, since it is larger than the sum of its proper divisors (4169854811).

221002302121 is an equidigital number, since it uses as much as digits as its factorization.

221002302121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4169854810.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 221002302121 its reverse (121203200122), we get a palindrome (342205502243).

The spelling of 221002302121 in words is "two hundred twenty-one billion, two million, three hundred two thousand, one hundred twenty-one".