1221199985 has 8 divisors (see below), whose sum is σ = 1505046696. Its totient is φ = 950555520.

The previous prime is 1221199963. The next prime is 1221200011. The reversal of 1221199985 is 5899911221.

It can be written as a sum of positive squares in 4 ways, for example, as 620557921 + 600642064 = 24911^2 + 24508^2 .

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

It is not a de Polignac number, because 1221199985 - 2¹² = 1221195889 is a prime.

It is a Duffinian number.

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, 3300356 + ... + 3300725.

It is an arithmetic number, because the mean of its divisors is an integer number (188130837).

Almost surely, 2^1221199985 is an apocalyptic number.

It is an amenable number.

1221199985 is a deficient number, since it is larger than the sum of its proper divisors (283846711).

1221199985 is an equidigital number, since it uses as much as digits as its factorization.

1221199985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6601123.

The product of its digits is 116640, while the sum is 47.

The square root of 1221199985 is about 34945.6719065466. The cubic root of 1221199985 is about 1068.8799485869.

The spelling of 1221199985 in words is "one billion, two hundred twenty-one million, one hundred ninety-nine thousand, nine hundred eighty-five".