1219981993 has 2 divisors, whose sum is σ = 1219981994. Its totient is φ = 1219981992.

The previous prime is 1219981991. The next prime is 1219982009. The reversal of 1219981993 is 3991899121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 929518144 + 290463849 = 30488^2 + 17043^2 .

It is a cyclic number.

It is not a de Polignac number, because 1219981993 - 2¹ = 1219981991 is a prime.

Together with 1219981991, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1219981993.

It is not a weakly prime, because it can be changed into another prime (1219981991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609990996 + 609990997.

It is an arithmetic number, because the mean of its divisors is an integer number (609990997).

Almost surely, 2^1219981993 is an apocalyptic number.

It is an amenable number.

1219981993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1219981993 is an equidigital number, since it uses as much as digits as its factorization.

1219981993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 52.

The square root of 1219981993 is about 34928.2406227396. The cubic root of 1219981993 is about 1068.5244730151.

The spelling of 1219981993 in words is "one billion, two hundred nineteen million, nine hundred eighty-one thousand, nine hundred ninety-three".