1989117617 has 4 divisors (see below), whose sum is σ = 1989210660. Its totient is φ = 1989024576.

The previous prime is 1989117601. The next prime is 1989117629. The reversal of 1989117617 is 7167119891.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 550887841 + 1438229776 = 23471^2 + 37924^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989117617 - 2⁴ = 1989117601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1989117677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3413 + ... + 63165.

It is an arithmetic number, because the mean of its divisors is an integer number (497302665).

Almost surely, 2^1989117617 is an apocalyptic number.

It is an amenable number.

1989117617 is a deficient number, since it is larger than the sum of its proper divisors (93043).

1989117617 is an equidigital number, since it uses as much as digits as its factorization.

1989117617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93042.

The product of its digits is 190512, while the sum is 50.

The square root of 1989117617 is about 44599.5248517291. The cubic root of 1989117617 is about 1257.6317354253.

The spelling of 1989117617 in words is "one billion, nine hundred eighty-nine million, one hundred seventeen thousand, six hundred seventeen".