919989 has 24 divisors (see below), whose sum is σ = 1609920. Its totient is φ = 494208.

The previous prime is 919979. The next prime is 920011. The reversal of 919989 is 989919.

919989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 919989 - 2¹⁹ = 395701 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 919989.

It is not an unprimeable number, because it can be changed into a prime (919939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 642 + ... + 1500.

It is an arithmetic number, because the mean of its divisors is an integer number (67080).

2⁹¹⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

919989 is a deficient number, since it is larger than the sum of its proper divisors (689931).

919989 is a wasteful number, since it uses less digits than its factorization.

919989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889 (or 886 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The square root of 919989 is about 959.1605704990. The cubic root of 919989 is about 97.2584949944.

The spelling of 919989 in words is "nine hundred nineteen thousand, nine hundred eighty-nine".