72688391 has 4 divisors (see below), whose sum is σ = 72772152. Its totient is φ = 72604632.

The previous prime is 72688381. The next prime is 72688403. The reversal of 72688391 is 19388627.

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

It is a cyclic number.

It is not a de Polignac number, because 72688391 - 2¹⁰ = 72687367 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 (72688381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40565 + ... + 42318.

It is an arithmetic number, because the mean of its divisors is an integer number (18193038).

Almost surely, 2^72688391 is an apocalyptic number.

72688391 is a deficient number, since it is larger than the sum of its proper divisors (83761).

72688391 is an equidigital number, since it uses as much as digits as its factorization.

72688391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83760.

The product of its digits is 145152, while the sum is 44.

The square root of 72688391 is about 8525.7487061255. The cubic root of 72688391 is about 417.3384049582.

The spelling of 72688391 in words is "seventy-two million, six hundred eighty-eight thousand, three hundred ninety-one".