1221105001 has 8 divisors (see below), whose sum is σ = 1287047880. Its totient is φ = 1156751232.

The previous prime is 1221104999. The next prime is 1221105071. The reversal of 1221105001 is 1005011221.

It can be written as a sum of positive squares in 4 ways, for example, as 659462400 + 561642601 = 25680^2 + 23699^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221105001 - 2¹ = 1221104999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221105071) 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, 395700 + ... + 398773.

It is an arithmetic number, because the mean of its divisors is an integer number (160880985).

Almost surely, 2^1221105001 is an apocalyptic number.

It is an amenable number.

1221105001 is a deficient number, since it is larger than the sum of its proper divisors (65942879).

1221105001 is an equidigital number, since it uses as much as digits as its factorization.

1221105001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794555.

The product of its (nonzero) digits is 20, while the sum is 13.

The square root of 1221105001 is about 34944.3128563147. The cubic root of 1221105001 is about 1068.8522356470.

Adding to 1221105001 its reverse (1005011221), we get a palindrome (2226116222).

The spelling of 1221105001 in words is "one billion, two hundred twenty-one million, one hundred five thousand, one".