100555581 has 32 divisors (see below), whose sum is σ = 162457600. Its totient is φ = 54043200.

The previous prime is 100555571. The next prime is 100555583. The reversal of 100555581 is 185555001.

It is not a de Polignac number, because 100555581 - 2⁷ = 100555453 is a prime.

It is a super-2 number, since 2×100555581² = 20222849740495122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100555583) 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 31 ways as a sum of consecutive naturals, for example, 59415 + ... + 61083.

It is an arithmetic number, because the mean of its divisors is an integer number (5076800).

Almost surely, 2^100555581 is an apocalyptic number.

It is an amenable number.

100555581 is a deficient number, since it is larger than the sum of its proper divisors (61902019).

100555581 is a wasteful number, since it uses less digits than its factorization.

100555581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849.

The product of its (nonzero) digits is 5000, while the sum is 30.

The square root of 100555581 is about 10027.7405730304. The cubic root of 100555581 is about 465.0168892004.

The spelling of 100555581 in words is "one hundred million, five hundred fifty-five thousand, five hundred eighty-one".