72391 has 4 divisors (see below), whose sum is σ = 78984. Its totient is φ = 65800.

The previous prime is 72383. The next prime is 72421. The reversal of 72391 is 19327.

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 72391 - 2³ = 72383 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a pancake number, because a pancake can be divided into 72391 parts by 380 straight cuts.

It is a Duffinian number.

72391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72341) 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, 3280 + ... + 3301.

It is an arithmetic number, because the mean of its divisors is an integer number (19746).

2⁷²³⁹¹ is an apocalyptic number.

72391 is a deficient number, since it is larger than the sum of its proper divisors (6593).

72391 is a wasteful number, since it uses less digits than its factorization.

72391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6592.

The product of its digits is 378, while the sum is 22.

The square root of 72391 is about 269.0557563034. The cubic root of 72391 is about 41.6768472901.

The spelling of 72391 in words is "seventy-two thousand, three hundred ninety-one".