19180643021 has 2 divisors, whose sum is σ = 19180643022. Its totient is φ = 19180643020.

The previous prime is 19180642997. The next prime is 19180643033. The reversal of 19180643021 is 12034608191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17579842921 + 1600800100 = 132589^2 + 40010^2 .

It is an emirp because it is prime and its reverse (12034608191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19180643021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19180645021) 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 as a sum of consecutive naturals, namely, 9590321510 + 9590321511.

It is an arithmetic number, because the mean of its divisors is an integer number (9590321511).

Almost surely, 2^19180643021 is an apocalyptic number.

It is an amenable number.

19180643021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19180643021 is an equidigital number, since it uses as much as digits as its factorization.

19180643021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The spelling of 19180643021 in words is "nineteen billion, one hundred eighty million, six hundred forty-three thousand, twenty-one".