10121021221 has 4 divisors (see below), whose sum is σ = 10121247532. Its totient is φ = 10120794912.

The previous prime is 10121021149. The next prime is 10121021263. The reversal of 10121021221 is 12212012101.

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 7531636225 + 2589384996 = 86785^2 + 50886^2 .

It is a cyclic number.

It is not a de Polignac number, because 10121021221 - 2³³ = 1531086629 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 (10121021021) 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, 21120 + ... + 143833.

It is an arithmetic number, because the mean of its divisors is an integer number (2530311883).

Almost surely, 2^10121021221 is an apocalyptic number.

It is an amenable number.

10121021221 is a deficient number, since it is larger than the sum of its proper divisors (226311).

10121021221 is an equidigital number, since it uses as much as digits as its factorization.

10121021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226310.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 10121021221 its reverse (12212012101), we get a palindrome (22333033322).

The spelling of 10121021221 in words is "ten billion, one hundred twenty-one million, twenty-one thousand, two hundred twenty-one".