19450137649 has 2 divisors, whose sum is σ = 19450137650. Its totient is φ = 19450137648.

The previous prime is 19450137643. The next prime is 19450137667. The reversal of 19450137649 is 94673105491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12057577249 + 7392560400 = 109807^2 + 85980^2 .

It is a cyclic number.

It is not a de Polignac number, because 19450137649 - 2¹⁵ = 19450104881 is a prime.

It is not a weakly prime, because it can be changed into another prime (19450137643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9725068824 + 9725068825.

It is an arithmetic number, because the mean of its divisors is an integer number (9725068825).

Almost surely, 2^19450137649 is an apocalyptic number.

It is an amenable number.

19450137649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19450137649 is an equidigital number, since it uses as much as digits as its factorization.

19450137649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 19450137649 in words is "nineteen billion, four hundred fifty million, one hundred thirty-seven thousand, six hundred forty-nine".