1628689 has 2 divisors, whose sum is σ = 1628690. Its totient is φ = 1628688.

The previous prime is 1628633. The next prime is 1628701. The reversal of 1628689 is 9868261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1040400 + 588289 = 1020^2 + 767^2 .

It is a cyclic number.

It is not a de Polignac number, because 1628689 - 2⁹ = 1628177 is a prime.

1628689 is a lucky number.

It is a nialpdrome in base 12.

It is not a weakly prime, because it can be changed into another prime (1628489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814344 + 814345.

It is an arithmetic number, because the mean of its divisors is an integer number (814345).

2^1628689 is an apocalyptic number.

It is an amenable number.

1628689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628689 is an equidigital number, since it uses as much as digits as its factorization.

1628689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 40.

The square root of 1628689 is about 1276.2010029772. The cubic root of 1628689 is about 117.6556320076.

The spelling of 1628689 in words is "one million, six hundred twenty-eight thousand, six hundred eighty-nine".