1923989 has 2 divisors, whose sum is σ = 1923990. Its totient is φ = 1923988.

The previous prime is 1923983. The next prime is 1923991. The reversal of 1923989 is 9893291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1876900 + 47089 = 1370^2 + 217^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1923989 is a prime.

Together with 1923991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1923983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 961994 + 961995.

It is an arithmetic number, because the mean of its divisors is an integer number (961995).

2^1923989 is an apocalyptic number.

It is an amenable number.

1923989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1923989 is an equidigital number, since it uses as much as digits as its factorization.

1923989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 41.

The square root of 1923989 is about 1387.0793055914. The cubic root of 1923989 is about 124.3753153532.

The spelling of 1923989 in words is "one million, nine hundred twenty-three thousand, nine hundred eighty-nine".