1023989 has 4 divisors (see below), whose sum is σ = 1045824. Its totient is φ = 1002156.

The previous prime is 1023977. The next prime is 1023991. The reversal of 1023989 is 9893201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9893201 = 17 ⋅581953.

It is a cyclic number.

It is not a de Polignac number, because 1023989 - 2⁴ = 1023973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1023949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10847 + ... + 10940.

It is an arithmetic number, because the mean of its divisors is an integer number (261456).

2^1023989 is an apocalyptic number.

It is an amenable number.

1023989 is a deficient number, since it is larger than the sum of its proper divisors (21835).

1023989 is an equidigital number, since it uses as much as digits as its factorization.

1023989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21834.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1023989 is about 1011.9234160746. The cubic root of 1023989 is about 100.7933230754.

The spelling of 1023989 in words is "one million, twenty-three thousand, nine hundred eighty-nine".