731531 has 2 divisors, whose sum is σ = 731532. Its totient is φ = 731530.

The previous prime is 731509. The next prime is 731539. The reversal of 731531 is 135137.

It is a happy number.

731531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-731531 is a prime.

It is a super-2 number, since 2×731531² = 1070275207922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (731539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 365765 + 365766.

It is an arithmetic number, because the mean of its divisors is an integer number (365766).

2⁷³¹⁵³¹ is an apocalyptic number.

731531 is the 383-rd centered decagonal number.

731531 is a deficient number, since it is larger than the sum of its proper divisors (1).

731531 is an equidigital number, since it uses as much as digits as its factorization.

731531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 315, while the sum is 20.

The square root of 731531 is about 855.2958552454. The cubic root of 731531 is about 90.1040360711.

Adding to 731531 its reverse (135137), we get a palindrome (866668).

The spelling of 731531 in words is "seven hundred thirty-one thousand, five hundred thirty-one".