19802057449 has 2 divisors, whose sum is σ = 19802057450. Its totient is φ = 19802057448.

The previous prime is 19802057447. The next prime is 19802057489. The reversal of 19802057449 is 94475020891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13215111849 + 6586945600 = 114957^2 + 81160^2 .

It is a cyclic number.

It is not a de Polignac number, because 19802057449 - 2¹ = 19802057447 is a prime.

Together with 19802057447, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19802057447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9901028724 + 9901028725.

It is an arithmetic number, because the mean of its divisors is an integer number (9901028725).

Almost surely, 2^19802057449 is an apocalyptic number.

It is an amenable number.

19802057449 is a deficient number, since it is larger than the sum of its proper divisors (1).

19802057449 is an equidigital number, since it uses as much as digits as its factorization.

19802057449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 19802057449 in words is "nineteen billion, eight hundred two million, fifty-seven thousand, four hundred forty-nine".