731986 has 8 divisors (see below), whose sum is σ = 1162620. Its totient is φ = 344448.

The previous prime is 731981. The next prime is 731999. The reversal of 731986 is 689137.

731986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 731025 + 961 = 855^2 + 31^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (34), and also a Moran number because the ratio is a prime number: 21529 = 731986 / (7 + 3 + 1 + 9 + 8 + 6).

It is not an unprimeable number, because it can be changed into a prime (731981) by changing a digit.

731986 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10731 + ... + 10798.

2⁷³¹⁹⁸⁶ is an apocalyptic number.

731986 is a deficient number, since it is larger than the sum of its proper divisors (430634).

731986 is a wasteful number, since it uses less digits than its factorization.

731986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21548.

The product of its digits is 9072, while the sum is 34.

The square root of 731986 is about 855.5618037290. The cubic root of 731986 is about 90.1227132652.

Subtracting from 731986 its reverse (689137), we obtain a square (42849 = 207²).

The spelling of 731986 in words is "seven hundred thirty-one thousand, nine hundred eighty-six".