818643489 has 4 divisors (see below), whose sum is σ = 1091524656. Its totient is φ = 545762324.

The previous prime is 818643487. The next prime is 818643491. The reversal of 818643489 is 984346818.

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 an interprime number because it is at equal distance from previous prime (818643487) and next prime (818643491).

It is a cyclic number.

It is not a de Polignac number, because 818643489 - 2¹ = 818643487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (818643487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136440579 + ... + 136440584.

It is an arithmetic number, because the mean of its divisors is an integer number (272881164).

Almost surely, 2^818643489 is an apocalyptic number.

It is an amenable number.

818643489 is a deficient number, since it is larger than the sum of its proper divisors (272881167).

818643489 is a wasteful number, since it uses less digits than its factorization.

818643489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272881166.

The product of its digits is 1327104, while the sum is 51.

The square root of 818643489 is about 28611.9466132593. The cubic root of 818643489 is about 935.4737469759.

The spelling of 818643489 in words is "eight hundred eighteen million, six hundred forty-three thousand, four hundred eighty-nine".