100028405 has 4 divisors (see below), whose sum is σ = 120034092. Its totient is φ = 80022720.

The previous prime is 100028393. The next prime is 100028441. The reversal of 100028405 is 504820001.

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

It can be written as a sum of positive squares in 2 ways, for example, as 55965361 + 44063044 = 7481^2 + 6638^2 .

It is not a de Polignac number, because 100028405 - 2⁴ = 100028389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 10002836 + ... + 10002845.

It is an arithmetic number, because the mean of its divisors is an integer number (30008523).

Almost surely, 2^100028405 is an apocalyptic number.

It is an amenable number.

100028405 is a deficient number, since it is larger than the sum of its proper divisors (20005687).

100028405 is an equidigital number, since it uses as much as digits as its factorization.

100028405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20005686.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 100028405 is about 10001.4201491588. The cubic root of 100028405 is about 464.2028273111.

Adding to 100028405 its reverse (504820001), we get a palindrome (604848406).

The spelling of 100028405 in words is "one hundred million, twenty-eight thousand, four hundred five".