1221120073 has 4 divisors (see below), whose sum is σ = 1221334420. Its totient is φ = 1220905728.

The previous prime is 1221120067. The next prime is 1221120077. The reversal of 1221120073 is 3700211221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 850480569 + 370639504 = 29163^2 + 19252^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221120073 - 2⁹ = 1221119561 is a prime.

It is a super-2 number, since 2×1221120073² = 2982268465367050658, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221120073.

It is not an unprimeable number, because it can be changed into a prime (1221120077) 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, 98388 + ... + 110101.

It is an arithmetic number, because the mean of its divisors is an integer number (305333605).

Almost surely, 2^1221120073 is an apocalyptic number.

It is an amenable number.

1221120073 is a deficient number, since it is larger than the sum of its proper divisors (214347).

1221120073 is an equidigital number, since it uses as much as digits as its factorization.

1221120073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214346.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 1221120073 is about 34944.5285130591. The cubic root of 1221120073 is about 1068.8566332144.

Adding to 1221120073 its reverse (3700211221), we get a palindrome (4921331294).

The spelling of 1221120073 in words is "one billion, two hundred twenty-one million, one hundred twenty thousand, seventy-three".