1261221199 has 8 divisors (see below), whose sum is σ = 1462909568. Its totient is φ = 1064911320.

The previous prime is 1261221193. The next prime is 1261221217. The reversal of 1261221199 is 9911221621.

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

It is a cyclic number.

It is not a de Polignac number, because 1261221199 - 2³ = 1261221191 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 (1261221191) 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 7 ways as a sum of consecutive naturals, for example, 1344117 + ... + 1345054.

It is an arithmetic number, because the mean of its divisors is an integer number (182863696).

Almost surely, 2^1261221199 is an apocalyptic number.

1261221199 is a deficient number, since it is larger than the sum of its proper divisors (201688369).

1261221199 is an equidigital number, since it uses as much as digits as its factorization.

1261221199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2689245.

The product of its digits is 3888, while the sum is 34.

The square root of 1261221199 is about 35513.6762248011. The cubic root of 1261221199 is about 1080.4311261722.

The spelling of 1261221199 in words is "one billion, two hundred sixty-one million, two hundred twenty-one thousand, one hundred ninety-nine".