1989090665 has 8 divisors (see below), whose sum is σ = 2463906048. Its totient is φ = 1539941040.

The previous prime is 1989090611. The next prime is 1989090683. The reversal of 1989090665 is 5660909891.

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

It is not a de Polignac number, because 1989090665 - 2⁸ = 1989090409 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6416267 + ... + 6416576.

It is an arithmetic number, because the mean of its divisors is an integer number (307988256).

Almost surely, 2^1989090665 is an apocalyptic number.

It is an amenable number.

1989090665 is a deficient number, since it is larger than the sum of its proper divisors (474815383).

1989090665 is a wasteful number, since it uses less digits than its factorization.

1989090665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12832879.

The product of its (nonzero) digits is 1049760, while the sum is 53.

The square root of 1989090665 is about 44599.2226950201. Note that the first 3 decimals coincide. The cubic root of 1989090665 is about 1257.6260552109.

The spelling of 1989090665 in words is "one billion, nine hundred eighty-nine million, ninety thousand, six hundred sixty-five".