1220002121 has 16 divisors (see below), whose sum is σ = 1331542800. Its totient is φ = 1111047168.

The previous prime is 1220002097. The next prime is 1220002139. The reversal of 1220002121 is 1212000221.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 672676096 + 547326025 = 25936^2 + 23395^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220002121 - 2⁶ = 1220002057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220002151) 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, 713015 + ... + 714723.

It is an arithmetic number, because the mean of its divisors is an integer number (83221425).

Almost surely, 2^1220002121 is an apocalyptic number.

It is an amenable number.

1220002121 is a deficient number, since it is larger than the sum of its proper divisors (111540679).

1220002121 is a wasteful number, since it uses less digits than its factorization.

1220002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2428.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1220002121 is about 34928.5287551594. The cubic root of 1220002121 is about 1068.5303493703.

Adding to 1220002121 its reverse (1212000221), we get a palindrome (2432002342).

The spelling of 1220002121 in words is "one billion, two hundred twenty million, two thousand, one hundred twenty-one".