72104309 has 4 divisors (see below), whose sum is σ = 72187404. Its totient is φ = 72021216.

The previous prime is 72104303. The next prime is 72104311. The reversal of 72104309 is 90340127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90340127 = 8501 ⋅10627.

It can be written as a sum of positive squares in 2 ways, for example, as 29398084 + 42706225 = 5422^2 + 6535^2 .

It is a cyclic number.

It is not a de Polignac number, because 72104309 - 2¹⁶ = 72038773 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 (72104303) 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, 40232 + ... + 41985.

It is an arithmetic number, because the mean of its divisors is an integer number (18046851).

Almost surely, 2^72104309 is an apocalyptic number.

It is an amenable number.

72104309 is a deficient number, since it is larger than the sum of its proper divisors (83095).

72104309 is an equidigital number, since it uses as much as digits as its factorization.

72104309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83094.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 72104309 is about 8491.4256164675. The cubic root of 72104309 is about 416.2175671748.

The spelling of 72104309 in words is "seventy-two million, one hundred four thousand, three hundred nine".