100001243 has 4 divisors (see below), whose sum is σ = 100022928. Its totient is φ = 99979560.

The previous prime is 100001227. The next prime is 100001303. The reversal of 100001243 is 342100001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 100001243 - 2⁴ = 100001227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100001203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 863 + ... + 14168.

It is an arithmetic number, because the mean of its divisors is an integer number (25005732).

Almost surely, 2^100001243 is an apocalyptic number.

100001243 is a deficient number, since it is larger than the sum of its proper divisors (21685).

100001243 is an equidigital number, since it uses as much as digits as its factorization.

100001243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21684.

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

The square root of 100001243 is about 10000.0621498069. The cubic root of 100001243 is about 464.1608065183.

Adding to 100001243 its reverse (342100001), we get a palindrome (442101244).

The spelling of 100001243 in words is "one hundred million, one thousand, two hundred forty-three".