10121212121221 has 8 divisors (see below), whose sum is σ = 10195425675000. Its totient is φ = 10047082380480.

The previous prime is 10121212121177. The next prime is 10121212121269. The reversal of 10121212121221 is 12212121212101.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3022643030625 + 7098569090596 = 1738575^2 + 2664314^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10121212121221 - 2¹³ = 10121212113029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10121212121281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20710846 + ... + 21193903.

It is an arithmetic number, because the mean of its divisors is an integer number (1274428209375).

Almost surely, 2^{10121212121221} is an apocalyptic number.

It is an amenable number.

10121212121221 is a deficient number, since it is larger than the sum of its proper divisors (74213553779).

10121212121221 is a wasteful number, since it uses less digits than its factorization.

10121212121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41906519.

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

Adding to 10121212121221 its reverse (12212121212101), we get a palindrome (22333333333322).

The spelling of 10121212121221 in words is "ten trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".