100809391 has 4 divisors (see below), whose sum is σ = 105192432. Its totient is φ = 96426352.

The previous prime is 100809353. The next prime is 100809409. The reversal of 100809391 is 193908001.

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

It is a cyclic number.

It is not a de Polignac number, because 100809391 - 2⁷ = 100809263 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100809311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2191486 + ... + 2191531.

It is an arithmetic number, because the mean of its divisors is an integer number (26298108).

Almost surely, 2^100809391 is an apocalyptic number.

100809391 is a deficient number, since it is larger than the sum of its proper divisors (4383041).

100809391 is an equidigital number, since it uses as much as digits as its factorization.

100809391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4383040.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 100809391 is about 10040.3879905111. The cubic root of 100809391 is about 465.4078065827.

The spelling of 100809391 in words is "one hundred million, eight hundred nine thousand, three hundred ninety-one".