1220001221999 has 8 divisors (see below), whose sum is σ = 1439264114688. Its totient is φ = 1011982580280.

The previous prime is 1220001221981. The next prime is 1220001222017. The reversal of 1220001221999 is 9991221000221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1220001221981) and next prime (1220001222017).

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

It is a de Polignac number, because none of the positive numbers 2^k-1220001221999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220001221399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2811062507 + ... + 2811062940.

It is an arithmetic number, because the mean of its divisors is an integer number (179908014336).

Almost surely, 2^{1220001221999} is an apocalyptic number.

1220001221999 is a deficient number, since it is larger than the sum of its proper divisors (219262892689).

1220001221999 is an equidigital number, since it uses as much as digits as its factorization.

1220001221999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5622125485.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 1220001221999 in words is "one trillion, two hundred twenty billion, one million, two hundred twenty-one thousand, nine hundred ninety-nine".