1243000001 has 8 divisors (see below), whose sum is σ = 1299121320. Its totient is φ = 1187762688.

The previous prime is 1242999973. The next prime is 1243000009. The reversal of 1243000001 is 1000003421.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 387144976 + 855855025 = 19676^2 + 29255^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243000001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1243000009) 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 in 7 ways as a sum of consecutive naturals, for example, 218126 + ... + 223751.

It is an arithmetic number, because the mean of its divisors is an integer number (162390165).

Almost surely, 2^1243000001 is an apocalyptic number.

It is an amenable number.

1243000001 is a deficient number, since it is larger than the sum of its proper divisors (56121319).

1243000001 is an equidigital number, since it uses as much as digits as its factorization.

1243000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442003.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 1243000001 is about 35256.2051417903. The cubic root of 1243000001 is about 1075.2027743682.

Adding to 1243000001 its reverse (1000003421), we get a palindrome (2243003422).

The spelling of 1243000001 in words is "one billion, two hundred forty-three million, one", and thus it is an aban number.