1220100121 has 4 divisors (see below), whose sum is σ = 1243120932. Its totient is φ = 1197079312.

The previous prime is 1220100107. The next prime is 1220100131. The reversal of 1220100121 is 1210010221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1210010221 = 7 ⋅172858603.

It can be written as a sum of positive squares in 2 ways, for example, as 785961225 + 434138896 = 28035^2 + 20836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220100121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220100098 and 1220100107.

It is not an unprimeable number, because it can be changed into a prime (1220100131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11510326 + ... + 11510431.

It is an arithmetic number, because the mean of its divisors is an integer number (310780233).

Almost surely, 2^1220100121 is an apocalyptic number.

It is an amenable number.

1220100121 is a deficient number, since it is larger than the sum of its proper divisors (23020811).

1220100121 is an equidigital number, since it uses as much as digits as its factorization.

1220100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23020810.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1220100121 is about 34929.9315916880. The cubic root of 1220100121 is about 1068.5589594764.

Adding to 1220100121 its reverse (1210010221), we get a palindrome (2430110342).

It can be divided in two parts, 1220100 and 121, that added together give a palindrome (1220221).

The spelling of 1220100121 in words is "one billion, two hundred twenty million, one hundred thousand, one hundred twenty-one".