102121122221 has 4 divisors (see below), whose sum is σ = 102121953600. Its totient is φ = 102120290844.

The previous prime is 102121122209. The next prime is 102121122223. The reversal of 102121122221 is 122221121201.

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: 122221121201 = 2011 ⋅60776291.

It is a cyclic number.

It is not a de Polignac number, because 102121122221 - 2¹⁸ = 102120860077 is a prime.

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 102121122221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102121122223) 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, 190931 + ... + 490608.

It is an arithmetic number, because the mean of its divisors is an integer number (25530488400).

Almost surely, 2^102121122221 is an apocalyptic number.

It is an amenable number.

102121122221 is a deficient number, since it is larger than the sum of its proper divisors (831379).

102121122221 is an equidigital number, since it uses as much as digits as its factorization.

102121122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831378.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 102121122221 its reverse (122221121201), we get a palindrome (224342243422).

The spelling of 102121122221 in words is "one hundred two billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".