1628989 has 2 divisors, whose sum is σ = 1628990. Its totient is φ = 1628988.

The previous prime is 1628987. The next prime is 1629007. The reversal of 1628989 is 9898261.

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., 1625625 + 3364 = 1275^2 + 58^2 .

It is a cyclic number.

It is not a de Polignac number, because 1628989 - 2¹ = 1628987 is a prime.

Together with 1628987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1628983) 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, 814494 + 814495.

It is an arithmetic number, because the mean of its divisors is an integer number (814495).

2^1628989 is an apocalyptic number.

It is an amenable number.

1628989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628989 is an equidigital number, since it uses as much as digits as its factorization.

1628989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 43.

The square root of 1628989 is about 1276.3185339091. The cubic root of 1628989 is about 117.6628555112.

The spelling of 1628989 in words is "one million, six hundred twenty-eight thousand, nine hundred eighty-nine".