1868989 has 2 divisors, whose sum is σ = 1868990. Its totient is φ = 1868988.

The previous prime is 1868987. The next prime is 1869029. The reversal of 1868989 is 9898681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1085764 + 783225 = 1042^2 + 885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1868989 - 2¹ = 1868987 is a prime.

Together with 1868987, it forms a pair of twin primes.

It is a Chen prime.

1868989 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1868983) 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, 934494 + 934495.

It is an arithmetic number, because the mean of its divisors is an integer number (934495).

2^1868989 is an apocalyptic number.

It is an amenable number.

1868989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868989 is an equidigital number, since it uses as much as digits as its factorization.

1868989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 49.

The square root of 1868989 is about 1367.1097249307. The cubic root of 1868989 is about 123.1786901989.

The spelling of 1868989 in words is "one million, eight hundred sixty-eight thousand, nine hundred eighty-nine".