72239309 has 4 divisors (see below), whose sum is σ = 72606204. Its totient is φ = 71872416.

The previous prime is 72239303. The next prime is 72239317. The reversal of 72239309 is 90393227.

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

It can be written as a sum of positive squares in 2 ways, for example, as 52852900 + 19386409 = 7270^2 + 4403^2 .

It is a cyclic number.

It is not a de Polignac number, because 72239309 - 2¹² = 72235213 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 (72239303) 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, 183152 + ... + 183545.

It is an arithmetic number, because the mean of its divisors is an integer number (18151551).

Almost surely, 2^72239309 is an apocalyptic number.

It is an amenable number.

72239309 is a deficient number, since it is larger than the sum of its proper divisors (366895).

72239309 is a wasteful number, since it uses less digits than its factorization.

72239309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366894.

The product of its (nonzero) digits is 20412, while the sum is 35.

The square root of 72239309 is about 8499.3710943810. The cubic root of 72239309 is about 416.4771648846.

The spelling of 72239309 in words is "seventy-two million, two hundred thirty-nine thousand, three hundred nine".