72731 has 4 divisors (see below), whose sum is σ = 73272. Its totient is φ = 72192.

The previous prime is 72727. The next prime is 72733. The reversal of 72731 is 13727.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 72731 - 2² = 72727 is a prime.

It is a super-2 number, since 2×72731² = 10579596722, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 72731.

It is not an unprimeable number, because it can be changed into a prime (72733) 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, 116 + ... + 398.

It is an arithmetic number, because the mean of its divisors is an integer number (18318).

2⁷²⁷³¹ is an apocalyptic number.

72731 is a deficient number, since it is larger than the sum of its proper divisors (541).

72731 is a wasteful number, since it uses less digits than its factorization.

72731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540.

The product of its digits is 294, while the sum is 20.

The square root of 72731 is about 269.6868554453. The cubic root of 72731 is about 41.7419935165.

The spelling of 72731 in words is "seventy-two thousand, seven hundred thirty-one".