100556 has 12 divisors (see below), whose sum is σ = 183792. Its totient is φ = 48048.

The previous prime is 100549. The next prime is 100559. The reversal of 100556 is 655001.

It is a super-2 number, since 2×100556² = 20223018272, which contains 22 as substring.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (100559) by changing a digit.

100556 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455 + ... + 638.

It is an arithmetic number, because the mean of its divisors is an integer number (15316).

2¹⁰⁰⁵⁵⁶ is an apocalyptic number.

100556 is the 170-th centered heptagonal number.

It is an amenable number.

100556 is a deficient number, since it is larger than the sum of its proper divisors (83236).

100556 is a wasteful number, since it uses less digits than its factorization.

100556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120 (or 1118 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 100556 is about 317.1056606243. The cubic root of 100556 is about 46.5017535085.

Adding to 100556 its reverse (655001), we get a palindrome (755557).

It can be divided in two parts, 1005 and 56, that multiplied together give a triangular number (56280 = T₃₃₅).

The spelling of 100556 in words is "one hundred thousand, five hundred fifty-six".