19446378449 has 2 divisors, whose sum is σ = 19446378450. Its totient is φ = 19446378448.

The previous prime is 19446378439. The next prime is 19446378481. The reversal of 19446378449 is 94487364491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12098460049 + 7347918400 = 109993^2 + 85720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19446378449 is a prime.

It is not a weakly prime, because it can be changed into another prime (19446378439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9723189224 + 9723189225.

It is an arithmetic number, because the mean of its divisors is an integer number (9723189225).

Almost surely, 2^19446378449 is an apocalyptic number.

It is an amenable number.

19446378449 is a deficient number, since it is larger than the sum of its proper divisors (1).

19446378449 is an equidigital number, since it uses as much as digits as its factorization.

19446378449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20901888, while the sum is 59.

The spelling of 19446378449 in words is "nineteen billion, four hundred forty-six million, three hundred seventy-eight thousand, four hundred forty-nine".