121221100121 has 16 divisors (see below), whose sum is σ = 135218626560. Its totient is φ = 107725499280.

The previous prime is 121221100109. The next prime is 121221100123. The reversal of 121221100121 is 121001122121.

It is a cyclic number.

It is not a de Polignac number, because 121221100121 - 2¹⁸ = 121220837977 is a prime.

It is a super-2 number, since 2×121221100121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221100096 and 121221100105.

It is not an unprimeable number, because it can be changed into a prime (121221100123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 285800 + ... + 569318.

It is an arithmetic number, because the mean of its divisors is an integer number (8451164160).

Almost surely, 2^121221100121 is an apocalyptic number.

121221100121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121221100121 is a deficient number, since it is larger than the sum of its proper divisors (13997526439).

121221100121 is a wasteful number, since it uses less digits than its factorization.

121221100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284404.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 121221100121 its reverse (121001122121), we get a palindrome (242222222242).

The spelling of 121221100121 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred thousand, one hundred twenty-one".