1189663421 has 4 divisors (see below), whose sum is σ = 1218679644. Its totient is φ = 1160647200.

The previous prime is 1189663403. The next prime is 1189663427. The reversal of 1189663421 is 1243669811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1243669811 = 31 ⋅40118381.

It can be written as a sum of positive squares in 2 ways, for example, as 696379321 + 493284100 = 26389^2 + 22210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1189663421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 29016181 = 1189663421 / (1 + 1 + 8 + 9 + 6 + 6 + 3 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1189663427) 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 3 ways as a sum of consecutive naturals, for example, 14508050 + ... + 14508131.

It is an arithmetic number, because the mean of its divisors is an integer number (304669911).

Almost surely, 2^1189663421 is an apocalyptic number.

It is an amenable number.

1189663421 is a deficient number, since it is larger than the sum of its proper divisors (29016223).

1189663421 is an equidigital number, since it uses as much as digits as its factorization.

1189663421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29016222.

The product of its digits is 62208, while the sum is 41.

The square root of 1189663421 is about 34491.4978074307. The cubic root of 1189663421 is about 1059.5985845073.

The spelling of 1189663421 in words is "one billion, one hundred eighty-nine million, six hundred sixty-three thousand, four hundred twenty-one".