1919689 has 2 divisors, whose sum is σ = 1919690. Its totient is φ = 1919688.

The previous prime is 1919677. The next prime is 1919693. The reversal of 1919689 is 9869191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1550025 + 369664 = 1245^2 + 608^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1919689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1919669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959844 + 959845.

It is an arithmetic number, because the mean of its divisors is an integer number (959845).

2^1919689 is an apocalyptic number.

It is an amenable number.

1919689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919689 is an equidigital number, since it uses as much as digits as its factorization.

1919689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 43.

The square root of 1919689 is about 1385.5284190517. The cubic root of 1919689 is about 124.2825891167.

The spelling of 1919689 in words is "one million, nine hundred nineteen thousand, six hundred eighty-nine".