1221793619 has 2 divisors, whose sum is σ = 1221793620. Its totient is φ = 1221793618.

The previous prime is 1221793609. The next prime is 1221793633. The reversal of 1221793619 is 9163971221.

It is a weak prime.

It is an emirp because it is prime and its reverse (9163971221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221793619 is a prime.

It is a super-2 number, since 2×1221793619² = 2985559294858234322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221793609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610896809 + 610896810.

It is an arithmetic number, because the mean of its divisors is an integer number (610896810).

Almost surely, 2^1221793619 is an apocalyptic number.

1221793619 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221793619 is an equidigital number, since it uses as much as digits as its factorization.

1221793619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 1221793619 is about 34954.1645444431. The cubic root of 1221793619 is about 1069.0531172460.

The spelling of 1221793619 in words is "one billion, two hundred twenty-one million, seven hundred ninety-three thousand, six hundred nineteen".