1918798432849 has 9 divisors (see below), whose sum is σ = 1933097680731. Its totient is φ = 1904604216720.

The previous prime is 1918798432843. The next prime is 1918798432877. The reversal of 1918798432849 is 9482348978191.

The square root of 1918798432849 is 1385207.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1127111339025 + 791687093824 = 1061655^2 + 889768^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1918798432849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1918798432843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 189768304 + ... + 189778414.

Almost surely, 2^{1918798432849} is an apocalyptic number.

1918798432849 is the 1385207-th square number.

1918798432849 is the 692604-th centered octagonal number.

It is an amenable number.

1918798432849 is a deficient number, since it is larger than the sum of its proper divisors (14299247882).

1918798432849 is an frugal number, since it uses more digits than its factorization.

1918798432849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20496 (or 10248 counting only the distinct ones).

The product of its digits is 250822656, while the sum is 73.

The spelling of 1918798432849 in words is "one trillion, nine hundred eighteen billion, seven hundred ninety-eight million, four hundred thirty-two thousand, eight hundred forty-nine".