1220243345 has 4 divisors (see below), whose sum is σ = 1464292020. Its totient is φ = 976194672.

The previous prime is 1220243309. The next prime is 1220243347. The reversal of 1220243345 is 5433420221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5433420221 = 461 ⋅11786161.

It can be written as a sum of positive squares in 2 ways, for example, as 614246656 + 605996689 = 24784^2 + 24617^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220243345 - 2¹⁰ = 1220242321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1220243347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122024330 + ... + 122024339.

It is an arithmetic number, because the mean of its divisors is an integer number (366073005).

Almost surely, 2^1220243345 is an apocalyptic number.

It is an amenable number.

1220243345 is a deficient number, since it is larger than the sum of its proper divisors (244048675).

1220243345 is an equidigital number, since it uses as much as digits as its factorization.

1220243345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244048674.

The product of its (nonzero) digits is 5760, while the sum is 26.

The square root of 1220243345 is about 34931.9816929988. The cubic root of 1220243345 is about 1068.6007695152.

Adding to 1220243345 its reverse (5433420221), we get a palindrome (6653663566).

The spelling of 1220243345 in words is "one billion, two hundred twenty million, two hundred forty-three thousand, three hundred forty-five".