100643903 has 4 divisors (see below), whose sum is σ = 101165568. Its totient is φ = 100122240.

The previous prime is 100643843. The next prime is 100643941. The reversal of 100643903 is 309346001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 309346001 = 53 ⋅5836717.

It is a cyclic number.

It is not a de Polignac number, because 100643903 - 2¹⁰ = 100642879 is a prime.

It is a super-2 number, since 2×100643903² = 20258390422146818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100643953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260543 + ... + 260928.

It is an arithmetic number, because the mean of its divisors is an integer number (25291392).

Almost surely, 2^100643903 is an apocalyptic number.

100643903 is a deficient number, since it is larger than the sum of its proper divisors (521665).

100643903 is an equidigital number, since it uses as much as digits as its factorization.

100643903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521664.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 100643903 is about 10032.1434898032. The cubic root of 100643903 is about 465.1529970203.

Adding to 100643903 its reverse (309346001), we get a palindrome (409989904).

The spelling of 100643903 in words is "one hundred million, six hundred forty-three thousand, nine hundred three".