18399810249871 has 2 divisors, whose sum is σ = 18399810249872. Its totient is φ = 18399810249870.

The previous prime is 18399810249857. The next prime is 18399810249959. The reversal of 18399810249871 is 17894201899381.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18399810249871 - 2²⁵ = 18399776695439 is a prime.

It is a super-2 number, since 2×18399810249871² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18399810249871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18399810249371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9199905124935 + 9199905124936.

It is an arithmetic number, because the mean of its divisors is an integer number (9199905124936).

Almost surely, 2^{18399810249871} is an apocalyptic number.

18399810249871 is a deficient number, since it is larger than the sum of its proper divisors (1).

18399810249871 is an equidigital number, since it uses as much as digits as its factorization.

18399810249871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62705664, while the sum is 70.

The spelling of 18399810249871 in words is "eighteen trillion, three hundred ninety-nine billion, eight hundred ten million, two hundred forty-nine thousand, eight hundred seventy-one".