72279809 has 4 divisors (see below), whose sum is σ = 82605504. Its totient is φ = 61954116.

The previous prime is 72279799. The next prime is 72279811. The reversal of 72279809 is 90897227.

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.

It is not a de Polignac number, because 72279809 - 2⁴ = 72279793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72279809.

It is not an unprimeable number, because it can be changed into a prime (72279829) 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, 5162837 + ... + 5162850.

It is an arithmetic number, because the mean of its divisors is an integer number (20651376).

Almost surely, 2^72279809 is an apocalyptic number.

It is an amenable number.

72279809 is a deficient number, since it is larger than the sum of its proper divisors (10325695).

72279809 is a wasteful number, since it uses less digits than its factorization.

72279809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10325694.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 72279809 is about 8501.7532897632. The cubic root of 72279809 is about 416.5549811237.

The spelling of 72279809 in words is "seventy-two million, two hundred seventy-nine thousand, eight hundred nine".