1243643 has 2 divisors, whose sum is σ = 1243644. Its totient is φ = 1243642.

The previous prime is 1243639. The next prime is 1243663. The reversal of 1243643 is 3463421.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1243643 - 2² = 1243639 is a prime.

It is a super-2 number, since 2×1243643² = 3093295822898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1243663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621821 + 621822.

It is an arithmetic number, because the mean of its divisors is an integer number (621822).

2^1243643 is an apocalyptic number.

1243643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243643 is an equidigital number, since it uses as much as digits as its factorization.

1243643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 23.

The square root of 1243643 is about 1115.1874281931. The cubic root of 1243643 is about 107.5388141794.

The spelling of 1243643 in words is "one million, two hundred forty-three thousand, six hundred forty-three".