1918867408509 has 8 divisors (see below), whose sum is σ = 2558829997152. Its totient is φ = 1279074879440.

The previous prime is 1918867408399. The next prime is 1918867408537. The reversal of 1918867408509 is 9058047688191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1918867408509 - 2³⁹ = 1369111594621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1918867408509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918867608509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42488562 + ... + 42533699.

It is an arithmetic number, because the mean of its divisors is an integer number (319853749644).

Almost surely, 2^{1918867408509} is an apocalyptic number.

It is an amenable number.

1918867408509 is a deficient number, since it is larger than the sum of its proper divisors (639962588643).

1918867408509 is an equidigital number, since it uses as much as digits as its factorization.

1918867408509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85029787.

The product of its (nonzero) digits is 34836480, while the sum is 66.

The spelling of 1918867408509 in words is "one trillion, nine hundred eighteen billion, eight hundred sixty-seven million, four hundred eight thousand, five hundred nine".