1221221101019 has 4 divisors (see below), whose sum is σ = 1221277444296. Its totient is φ = 1221164757744.

The previous prime is 1221221100977. The next prime is 1221221101039. The reversal of 1221221101019 is 9101011221221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221221101019 is a prime.

It is a super-2 number, since 2×1221221101019² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221221100985 and 1221221101003.

It is not an unprimeable number, because it can be changed into a prime (1221221101039) 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 3 ways as a sum of consecutive naturals, for example, 28139114 + ... + 28182479.

It is an arithmetic number, because the mean of its divisors is an integer number (305319361074).

Almost surely, 2^{1221221101019} is an apocalyptic number.

1221221101019 is a deficient number, since it is larger than the sum of its proper divisors (56343277).

1221221101019 is an equidigital number, since it uses as much as digits as its factorization.

1221221101019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56343276.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 1221221101019 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, nineteen".