121200021221 has 8 divisors (see below), whose sum is σ = 128464109784. Its totient is φ = 113950896640.

The previous prime is 121200021211. The next prime is 121200021223. The reversal of 121200021221 is 122120002121.

It can be written as a sum of positive squares in 4 ways, for example, as 37785916996 + 83414104225 = 194386^2 + 288815^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-121200021221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121200021196 and 121200021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121200021223) 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, 3724310 + ... + 3756711.

It is an arithmetic number, because the mean of its divisors is an integer number (16058013723).

Almost surely, 2^121200021221 is an apocalyptic number.

It is an amenable number.

121200021221 is a deficient number, since it is larger than the sum of its proper divisors (7264088563).

121200021221 is an equidigital number, since it uses as much as digits as its factorization.

121200021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7481991.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 121200021221 its reverse (122120002121), we get a palindrome (243320023342).

The spelling of 121200021221 in words is "one hundred twenty-one billion, two hundred million, twenty-one thousand, two hundred twenty-one".