19361698621 has 2 divisors, whose sum is σ = 19361698622. Its totient is φ = 19361698620.

The previous prime is 19361698619. The next prime is 19361698639. The reversal of 19361698621 is 12689616391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10750786596 + 8610912025 = 103686^2 + 92795^2 .

It is a cyclic number.

It is not a de Polignac number, because 19361698621 - 2¹ = 19361698619 is a prime.

Together with 19361698619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19361698721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9680849310 + 9680849311.

It is an arithmetic number, because the mean of its divisors is an integer number (9680849311).

Almost surely, 2^19361698621 is an apocalyptic number.

It is an amenable number.

19361698621 is a deficient number, since it is larger than the sum of its proper divisors (1).

19361698621 is an equidigital number, since it uses as much as digits as its factorization.

19361698621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 52.

The spelling of 19361698621 in words is "nineteen billion, three hundred sixty-one million, six hundred ninety-eight thousand, six hundred twenty-one".