109173957509 has 4 divisors (see below), whose sum is σ = 109213104780. Its totient is φ = 109134810240.

The previous prime is 109173957457. The next prime is 109173957539. The reversal of 109173957509 is 905759371901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 905759371901 = 17 ⋅53279963053.

It can be written as a sum of positive squares in 2 ways, for example, as 32120525284 + 77053432225 = 179222^2 + 277585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-109173957509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109173957539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19569452 + ... + 19575029.

It is an arithmetic number, because the mean of its divisors is an integer number (27303276195).

Almost surely, 2^109173957509 is an apocalyptic number.

It is an amenable number.

109173957509 is a deficient number, since it is larger than the sum of its proper divisors (39147271).

109173957509 is an equidigital number, since it uses as much as digits as its factorization.

109173957509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39147270.

The product of its (nonzero) digits is 2679075, while the sum is 56.

The spelling of 109173957509 in words is "one hundred nine billion, one hundred seventy-three million, nine hundred fifty-seven thousand, five hundred nine".