1643123 has 2 divisors, whose sum is σ = 1643124. Its totient is φ = 1643122.

The previous prime is 1643099. The next prime is 1643129. The reversal of 1643123 is 3213461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1643123 - 2¹⁴ = 1626739 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1643095 and 1643104.

It is not a weakly prime, because it can be changed into another prime (1643129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821561 + 821562.

It is an arithmetic number, because the mean of its divisors is an integer number (821562).

2^1643123 is an apocalyptic number.

1643123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643123 is an equidigital number, since it uses as much as digits as its factorization.

1643123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 20.

The square root of 1643123 is about 1281.8435942033. The cubic root of 1643123 is about 118.0021784526.

Adding to 1643123 its reverse (3213461), we get a palindrome (4856584).

The spelling of 1643123 in words is "one million, six hundred forty-three thousand, one hundred twenty-three".