1221000019 has 4 divisors (see below), whose sum is σ = 1229194800. Its totient is φ = 1212805240.

The previous prime is 1221000017. The next prime is 1221000029. The reversal of 1221000019 is 9100001221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221000019 - 2¹ = 1221000017 is a prime.

It is a super-2 number, since 2×1221000019² = 2981682092796000722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220999966 and 1221000011.

It is not an unprimeable number, because it can be changed into a prime (1221000017) 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, 4097167 + ... + 4097464.

It is an arithmetic number, because the mean of its divisors is an integer number (307298700).

Almost surely, 2^1221000019 is an apocalyptic number.

1221000019 is a deficient number, since it is larger than the sum of its proper divisors (8194781).

1221000019 is an equidigital number, since it uses as much as digits as its factorization.

1221000019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8194780.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1221000019 is about 34942.8106911851. The cubic root of 1221000019 is about 1068.8216039756.

The spelling of 1221000019 in words is "one billion, two hundred twenty-one million, nineteen", and thus it is an aban number.