1662643 has 2 divisors, whose sum is σ = 1662644. Its totient is φ = 1662642.

The previous prime is 1662641. The next prime is 1662653. The reversal of 1662643 is 3462661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1662643 - 2¹ = 1662641 is a prime.

Together with 1662641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1662641) 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, 831321 + 831322.

It is an arithmetic number, because the mean of its divisors is an integer number (831322).

2^1662643 is an apocalyptic number.

1662643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1662643 is an equidigital number, since it uses as much as digits as its factorization.

1662643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 28.

The square root of 1662643 is about 1289.4351476519. The cubic root of 1662643 is about 118.4676215787.

It can be divided in two parts, 166 and 2643, that added together give a square (2809 = 53²).

The spelling of 1662643 in words is "one million, six hundred sixty-two thousand, six hundred forty-three".