165889899 has 12 divisors (see below), whose sum is σ = 273850096. Its totient is φ = 94794192.

The previous prime is 165889891. The next prime is 165889901. The reversal of 165889899 is 998988561.

It is not a de Polignac number, because 165889899 - 2³ = 165889891 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 2633173 = 165889899 / (1 + 6 + 5 + 8 + 8 + 9 + 8 + 9 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165889891) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1316524 + ... + 1316649.

Almost surely, 2^165889899 is an apocalyptic number.

165889899 is a deficient number, since it is larger than the sum of its proper divisors (107960197).

165889899 is a wasteful number, since it uses less digits than its factorization.

165889899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2633186 (or 2633183 counting only the distinct ones).

The product of its digits is 11197440, while the sum is 63.

The square root of 165889899 is about 12879.8252705539. The cubic root of 165889899 is about 549.4649330730.

The spelling of 165889899 in words is "one hundred sixty-five million, eight hundred eighty-nine thousand, eight hundred ninety-nine".