19213198021 has 2 divisors, whose sum is σ = 19213198022. Its totient is φ = 19213198020.

The previous prime is 19213197973. The next prime is 19213198027. The reversal of 19213198021 is 12089131291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13571085025 + 5642112996 = 116495^2 + 75114^2 .

It is an emirp because it is prime and its reverse (12089131291) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19213198021 - 2²⁷ = 19078980293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19213198027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9606599010 + 9606599011.

It is an arithmetic number, because the mean of its divisors is an integer number (9606599011).

Almost surely, 2^19213198021 is an apocalyptic number.

It is an amenable number.

19213198021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19213198021 is an equidigital number, since it uses as much as digits as its factorization.

19213198021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 37.

The spelling of 19213198021 in words is "nineteen billion, two hundred thirteen million, one hundred ninety-eight thousand, twenty-one".