72518399 has 4 divisors (see below), whose sum is σ = 72894336. Its totient is φ = 72142464.

The previous prime is 72518389. The next prime is 72518401. The reversal of 72518399 is 99381527.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99381527 = 7 ⋅14197361.

It is a cyclic number.

It is not a de Polignac number, because 72518399 - 2²⁰ = 71469823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72518389) 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, 187679 + ... + 188064.

It is an arithmetic number, because the mean of its divisors is an integer number (18223584).

Almost surely, 2^72518399 is an apocalyptic number.

72518399 is a deficient number, since it is larger than the sum of its proper divisors (375937).

72518399 is a wasteful number, since it uses less digits than its factorization.

72518399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375936.

The product of its digits is 136080, while the sum is 44.

The square root of 72518399 is about 8515.7735409063. The cubic root of 72518399 is about 417.0128162113.

The spelling of 72518399 in words is "seventy-two million, five hundred eighteen thousand, three hundred ninety-nine".