1221055707 has 4 divisors (see below), whose sum is σ = 1628074280. Its totient is φ = 814037136.

The previous prime is 1221055697. The next prime is 1221055741. The reversal of 1221055707 is 7075501221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7075501221 = 3 ⋅2358500407.

It is not a de Polignac number, because 1221055707 - 2²⁷ = 1086837979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221055747) 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, 203509282 + ... + 203509287.

It is an arithmetic number, because the mean of its divisors is an integer number (407018570).

Almost surely, 2^1221055707 is an apocalyptic number.

1221055707 is a deficient number, since it is larger than the sum of its proper divisors (407018573).

1221055707 is an equidigital number, since it uses as much as digits as its factorization.

1221055707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407018572.

The product of its (nonzero) digits is 4900, while the sum is 30.

The square root of 1221055707 is about 34943.6075269855. The cubic root of 1221055707 is about 1068.8378528514.

Adding to 1221055707 its reverse (7075501221), we get a palindrome (8296556928).

The spelling of 1221055707 in words is "one billion, two hundred twenty-one million, fifty-five thousand, seven hundred seven".