17817965849 has 4 divisors (see below), whose sum is σ = 17818798080. Its totient is φ = 17817133620.

The previous prime is 17817965813. The next prime is 17817965873. The reversal of 17817965849 is 94856971871.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17817965849 is a prime.

It is a super-2 number, since 2×17817965849² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17817965899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383129 + ... + 427110.

It is an arithmetic number, because the mean of its divisors is an integer number (4454699520).

Almost surely, 2^17817965849 is an apocalyptic number.

It is an amenable number.

17817965849 is a deficient number, since it is larger than the sum of its proper divisors (832231).

17817965849 is an equidigital number, since it uses as much as digits as its factorization.

17817965849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832230.

The product of its digits is 30481920, while the sum is 65.

The spelling of 17817965849 in words is "seventeen billion, eight hundred seventeen million, nine hundred sixty-five thousand, eight hundred forty-nine".