1221001305 has 8 divisors (see below), whose sum is σ = 1953602112. Its totient is φ = 651200688.

The previous prime is 1221001277. The next prime is 1221001337. The reversal of 1221001305 is 5031001221.

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

It is not a de Polignac number, because 1221001305 - 2¹¹ = 1220999257 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 81400087 = 1221001305 / (1 + 2 + 2 + 1 + 0 + 0 + 1 + 3 + 0 + 5).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 40700029 + ... + 40700058.

It is an arithmetic number, because the mean of its divisors is an integer number (244200264).

Almost surely, 2^1221001305 is an apocalyptic number.

1221001305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221001305 is a deficient number, since it is larger than the sum of its proper divisors (732600807).

1221001305 is an equidigital number, since it uses as much as digits as its factorization.

1221001305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81400095.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 1221001305 is about 34942.8290926765. The cubic root of 1221001305 is about 1068.8219792156.

Adding to 1221001305 its reverse (5031001221), we get a palindrome (6252002526).

The spelling of 1221001305 in words is "one billion, two hundred twenty-one million, one thousand, three hundred five".