1221245073 has 8 divisors (see below), whose sum is σ = 1809252000. Its totient is φ = 814163364.

The previous prime is 1221245059. The next prime is 1221245101. The reversal of 1221245073 is 3705421221.

It is not a de Polignac number, because 1221245073 - 2⁴ = 1221245057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 45231299 = 1221245073 / (1 + 2 + 2 + 1 + 2 + 4 + 5 + 0 + 7 + 3).

It is not an unprimeable number, because it can be changed into a prime (1221245033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22615623 + ... + 22615676.

It is an arithmetic number, because the mean of its divisors is an integer number (226156500).

Almost surely, 2^1221245073 is an apocalyptic number.

It is an amenable number.

1221245073 is a deficient number, since it is larger than the sum of its proper divisors (588006927).

1221245073 is an equidigital number, since it uses as much as digits as its factorization.

1221245073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45231308 (or 45231302 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 1221245073 is about 34946.3170162465. The cubic root of 1221245073 is about 1068.8931031525.

Adding to 1221245073 its reverse (3705421221), we get a palindrome (4926666294).

The spelling of 1221245073 in words is "one billion, two hundred twenty-one million, two hundred forty-five thousand, seventy-three".