100809409 has 2 divisors, whose sum is σ = 100809410. Its totient is φ = 100809408.

The previous prime is 100809353. The next prime is 100809463. The reversal of 100809409 is 904908001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52200625 + 48608784 = 7225^2 + 6972^2 .

It is a cyclic number.

It is not a de Polignac number, because 100809409 - 2⁷ = 100809281 is a prime.

It is not a weakly prime, because it can be changed into another prime (100809509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50404704 + 50404705.

It is an arithmetic number, because the mean of its divisors is an integer number (50404705).

Almost surely, 2^100809409 is an apocalyptic number.

It is an amenable number.

100809409 is a deficient number, since it is larger than the sum of its proper divisors (1).

100809409 is an equidigital number, since it uses as much as digits as its factorization.

100809409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 100809409 is about 10040.3888868908. The cubic root of 100809409 is about 465.4078342829.

The spelling of 100809409 in words is "one hundred million, eight hundred nine thousand, four hundred nine".