109781409 has 4 divisors (see below), whose sum is σ = 146375216. Its totient is φ = 73187604.

The previous prime is 109781389. The next prime is 109781423. The reversal of 109781409 is 904187901.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 904187901 = 3 ⋅301395967.

It is not a de Polignac number, because 109781409 - 2⁵ = 109781377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109781429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18296899 + ... + 18296904.

It is an arithmetic number, because the mean of its divisors is an integer number (36593804).

Almost surely, 2^109781409 is an apocalyptic number.

It is an amenable number.

109781409 is a deficient number, since it is larger than the sum of its proper divisors (36593807).

109781409 is an equidigital number, since it uses as much as digits as its factorization.

109781409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36593806.

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 109781409 is about 10477.6623824210. The cubic root of 109781409 is about 478.8243930415.

The spelling of 109781409 in words is "one hundred nine million, seven hundred eighty-one thousand, four hundred nine".