72817889 has 4 divisors (see below), whose sum is σ = 72891924. Its totient is φ = 72743856.

The previous prime is 72817883. The next prime is 72817897. The reversal of 72817889 is 98871827.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98871827 = 479 ⋅206413.

It can be written as a sum of positive squares in 2 ways, for example, as 66961489 + 5856400 = 8183^2 + 2420^2 .

It is a cyclic number.

It is not a de Polignac number, because 72817889 - 2⁴ = 72817873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72817883) 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, 35522 + ... + 37515.

It is an arithmetic number, because the mean of its divisors is an integer number (18222981).

Almost surely, 2^72817889 is an apocalyptic number.

It is an amenable number.

72817889 is a deficient number, since it is larger than the sum of its proper divisors (74035).

72817889 is an equidigital number, since it uses as much as digits as its factorization.

72817889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74034.

The product of its digits is 451584, while the sum is 50.

The square root of 72817889 is about 8533.3398502579. The cubic root of 72817889 is about 417.5860943321.

The spelling of 72817889 in words is "seventy-two million, eight hundred seventeen thousand, eight hundred eighty-nine".