431581 has 2 divisors, whose sum is σ = 431582. Its totient is φ = 431580.

The previous prime is 431567. The next prime is 431597. The reversal of 431581 is 185134.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 210681 = 470^2 + 459^2 .

It is a cyclic number.

It is not a de Polignac number, because 431581 - 2¹³ = 423389 is a prime.

It is a super-2 number, since 2×431581² = 372524319122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (431521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215790 + 215791.

It is an arithmetic number, because the mean of its divisors is an integer number (215791).

2⁴³¹⁵⁸¹ is an apocalyptic number.

It is an amenable number.

431581 is a deficient number, since it is larger than the sum of its proper divisors (1).

431581 is an equidigital number, since it uses as much as digits as its factorization.

431581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 22.

The square root of 431581 is about 656.9482475812. The cubic root of 431581 is about 75.5708149527.

The spelling of 431581 in words is "four hundred thirty-one thousand, five hundred eighty-one".