1221202145 has 16 divisors (see below), whose sum is σ = 1488913920. Its totient is φ = 961396800.

The previous prime is 1221202133. The next prime is 1221202159. The reversal of 1221202145 is 5412021221.

It is not a de Polignac number, because 1221202145 - 2¹⁸ = 1220940001 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 117875 + ... + 127815.

It is an arithmetic number, because the mean of its divisors is an integer number (93057120).

Almost surely, 2^1221202145 is an apocalyptic number.

It is an amenable number.

1221202145 is a deficient number, since it is larger than the sum of its proper divisors (267711775).

1221202145 is an equidigital number, since it uses as much as digits as its factorization.

1221202145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10336.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 1221202145 is about 34945.7028116477. The cubic root of 1221202145 is about 1068.8805787811.

Adding to 1221202145 its reverse (5412021221), we get a palindrome (6633223366).

The spelling of 1221202145 in words is "one billion, two hundred twenty-one million, two hundred two thousand, one hundred forty-five".