72733309 has 4 divisors (see below), whose sum is σ = 79345440. Its totient is φ = 66121180.

The previous prime is 72733301. The next prime is 72733333. The reversal of 72733309 is 90333727.

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: 90333727 = 11 ⋅8212157.

It is a cyclic number.

It is not a de Polignac number, because 72733309 - 2³ = 72733301 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 (72733301) 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, 3306049 + ... + 3306070.

It is an arithmetic number, because the mean of its divisors is an integer number (19836360).

Almost surely, 2^72733309 is an apocalyptic number.

It is an amenable number.

72733309 is a deficient number, since it is larger than the sum of its proper divisors (6612131).

72733309 is a wasteful number, since it uses less digits than its factorization.

72733309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6612130.

The product of its (nonzero) digits is 23814, while the sum is 34.

The square root of 72733309 is about 8528.3825547404. The cubic root of 72733309 is about 417.4243524122.

The spelling of 72733309 in words is "seventy-two million, seven hundred thirty-three thousand, three hundred nine".