19440968621 has 2 divisors, whose sum is σ = 19440968622. Its totient is φ = 19440968620.

The previous prime is 19440968609. The next prime is 19440968623. The reversal of 19440968621 is 12686904491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19433754025 + 7214596 = 139405^2 + 2686^2 .

It is a cyclic number.

It is not a de Polignac number, because 19440968621 - 2²² = 19436774317 is a prime.

Together with 19440968623, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19440968621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19440968623) 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, 9720484310 + 9720484311.

It is an arithmetic number, because the mean of its divisors is an integer number (9720484311).

Almost surely, 2^19440968621 is an apocalyptic number.

It is an amenable number.

19440968621 is a deficient number, since it is larger than the sum of its proper divisors (1).

19440968621 is an equidigital number, since it uses as much as digits as its factorization.

19440968621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 50.

The spelling of 19440968621 in words is "nineteen billion, four hundred forty million, nine hundred sixty-eight thousand, six hundred twenty-one".