17890423849 has 2 divisors, whose sum is σ = 17890423850. Its totient is φ = 17890423848.

The previous prime is 17890423787. The next prime is 17890423877. The reversal of 17890423849 is 94832409871.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12934967824 + 4955456025 = 113732^2 + 70395^2 .

It is a cyclic number.

It is not a de Polignac number, because 17890423849 - 2²¹ = 17888326697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 17890423849.

It is not a weakly prime, because it can be changed into another prime (17890423049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8945211924 + 8945211925.

It is an arithmetic number, because the mean of its divisors is an integer number (8945211925).

Almost surely, 2^17890423849 is an apocalyptic number.

It is an amenable number.

17890423849 is a deficient number, since it is larger than the sum of its proper divisors (1).

17890423849 is an equidigital number, since it uses as much as digits as its factorization.

17890423849 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 17890423849 in words is "seventeen billion, eight hundred ninety million, four hundred twenty-three thousand, eight hundred forty-nine".