72388889 has 6 divisors (see below), whose sum is σ = 75673626. Its totient is φ = 69241040.

The previous prime is 72388859. The next prime is 72388891. The reversal of 72388889 is 98888327.

It can be written as a sum of positive squares in only one way, i.e., 66667225 + 5721664 = 8165^2 + 2392^2 .

It is a de Polignac number, because none of the positive numbers 2^k-72388889 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 72388889.

It is not an unprimeable number, because it can be changed into a prime (72388859) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67892 + ... + 68949.

It is an arithmetic number, because the mean of its divisors is an integer number (12612271).

Almost surely, 2^72388889 is an apocalyptic number.

It is an amenable number.

72388889 is a deficient number, since it is larger than the sum of its proper divisors (3284737).

72388889 is a wasteful number, since it uses less digits than its factorization.

72388889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136887 (or 136864 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 53.

The square root of 72388889 is about 8508.1660185965. The cubic root of 72388889 is about 416.7644217215.

The spelling of 72388889 in words is "seventy-two million, three hundred eighty-eight thousand, eight hundred eighty-nine".