72432809 has 4 divisors (see below), whose sum is σ = 73349760. Its totient is φ = 71515860.

The previous prime is 72432797. The next prime is 72432839. The reversal of 72432809 is 90823427.

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 a cyclic number.

It is not a de Polignac number, because 72432809 - 2⁸ = 72432553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72432839) 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, 458357 + ... + 458514.

It is an arithmetic number, because the mean of its divisors is an integer number (18337440).

Almost surely, 2^72432809 is an apocalyptic number.

72432809 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

It is an amenable number.

72432809 is a deficient number, since it is larger than the sum of its proper divisors (916951).

72432809 is an equidigital number, since it uses as much as digits as its factorization.

72432809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916950.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 72432809 is about 8510.7466769961. The cubic root of 72432809 is about 416.8486915269.

It can be divided in two parts, 724 and 32809, that added together give a palindrome (33533).

The spelling of 72432809 in words is "seventy-two million, four hundred thirty-two thousand, eight hundred nine".