100543021 has 4 divisors (see below), whose sum is σ = 102247200. Its totient is φ = 98838844.

The previous prime is 100543019. The next prime is 100543039. The reversal of 100543021 is 120345001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120345001 = 7 ⋅17192143.

It is a cyclic number.

It is not a de Polignac number, because 100543021 - 2¹ = 100543019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100542986 and 100543004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100543721) 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, 852001 + ... + 852118.

It is an arithmetic number, because the mean of its divisors is an integer number (25561800).

Almost surely, 2^100543021 is an apocalyptic number.

It is an amenable number.

100543021 is a deficient number, since it is larger than the sum of its proper divisors (1704179).

100543021 is an equidigital number, since it uses as much as digits as its factorization.

100543021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1704178.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 100543021 is about 10027.1142907618. The cubic root of 100543021 is about 464.9975272540.

Adding to 100543021 its reverse (120345001), we get a palindrome (220888022).

The spelling of 100543021 in words is "one hundred million, five hundred forty-three thousand, twenty-one".