121220210111221 has 16 divisors (see below), whose sum is σ = 132411244719600. Its totient is φ = 110306226498048.

The previous prime is 121220210111191. The next prime is 121220210111233. The reversal of 121220210111221 is 122111012022121.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 33691349580625 + 87528860530596 = 5804425^2 + 9355686^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220210111221 - 2²¹ = 121220208014069 is a prime.

It is a super-2 number, since 2×121220210111221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220210117221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216845416 + ... + 217403713.

It is an arithmetic number, because the mean of its divisors is an integer number (8275702794975).

Almost surely, 2^{121220210111221} is an apocalyptic number.

It is an amenable number.

121220210111221 is a deficient number, since it is larger than the sum of its proper divisors (11191034608379).

121220210111221 is a wasteful number, since it uses less digits than its factorization.

121220210111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434249448.

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

Adding to 121220210111221 its reverse (122111012022121), we get a palindrome (243331222133342).

The spelling of 121220210111221 in words is "one hundred twenty-one trillion, two hundred twenty billion, two hundred ten million, one hundred eleven thousand, two hundred twenty-one".