72399689 has 4 divisors (see below), whose sum is σ = 74896260. Its totient is φ = 69903120.

The previous prime is 72399641. The next prime is 72399697. The reversal of 72399689 is 98699327.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26091664 + 46308025 = 5108^2 + 6805^2 .

It is a cyclic number.

It is not a de Polignac number, because 72399689 - 2⁸ = 72399433 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 72399689.

It is not an unprimeable number, because it can be changed into a prime (72393689) 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, 1248242 + ... + 1248299.

It is an arithmetic number, because the mean of its divisors is an integer number (18724065).

Almost surely, 2^72399689 is an apocalyptic number.

It is an amenable number.

72399689 is a deficient number, since it is larger than the sum of its proper divisors (2496571).

72399689 is a wasteful number, since it uses less digits than its factorization.

72399689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496570.

The product of its digits is 1469664, while the sum is 53.

The square root of 72399689 is about 8508.8006792967. The cubic root of 72399689 is about 416.7851469644.

The spelling of 72399689 in words is "seventy-two million, three hundred ninety-nine thousand, six hundred eighty-nine".