731138 has 4 divisors (see below), whose sum is σ = 1096710. Its totient is φ = 365568.

The previous prime is 731117. The next prime is 731141. The reversal of 731138 is 831137.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 831137 = 163 ⋅5099.

It can be written as a sum of positive squares in only one way, i.e., 693889 + 37249 = 833^2 + 193^2 .

It is an unprimeable number.

731138 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 as a sum of consecutive naturals, namely, 182783 + ... + 182786.

2⁷³¹¹³⁸ is an apocalyptic number.

731138 is a deficient number, since it is larger than the sum of its proper divisors (365572).

731138 is a wasteful number, since it uses less digits than its factorization.

731138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365571.

The product of its digits is 504, while the sum is 23.

The square root of 731138 is about 855.0660793179. The cubic root of 731138 is about 90.0878976667.

Subtracting 731138 from its reverse (831137), we obtain a palindrome (99999).

The spelling of 731138 in words is "seven hundred thirty-one thousand, one hundred thirty-eight".