1221312199 has 2 divisors, whose sum is σ = 1221312200. Its totient is φ = 1221312198.

The previous prime is 1221312173. The next prime is 1221312203. The reversal of 1221312199 is 9912131221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221312199 - 2¹¹ = 1221310151 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221312199.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221312149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610656099 + 610656100.

It is an arithmetic number, because the mean of its divisors is an integer number (610656100).

Almost surely, 2^1221312199 is an apocalyptic number.

1221312199 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221312199 is an equidigital number, since it uses as much as digits as its factorization.

1221312199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 31.

The square root of 1221312199 is about 34947.2774189922. The cubic root of 1221312199 is about 1068.9126867740.

The spelling of 1221312199 in words is "one billion, two hundred twenty-one million, three hundred twelve thousand, one hundred ninety-nine".