743581 has 4 divisors (see below), whose sum is σ = 745852. Its totient is φ = 741312.

The previous prime is 743579. The next prime is 743591. The reversal of 743581 is 185347.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 185347 = 73 ⋅2539.

It can be written as a sum of positive squares in 2 ways, for example, as 210681 + 532900 = 459^2 + 730^2 .

It is a cyclic number.

It is not a de Polignac number, because 743581 - 2¹ = 743579 is a prime.

It is a super-2 number, since 2×743581² = 1105825407122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (743551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540 + ... + 1333.

It is an arithmetic number, because the mean of its divisors is an integer number (186463).

743581 is a Friedman number, since it can be written as 85*4*3^7+1, using all its digits and the basic arithmetic operations.

2⁷⁴³⁵⁸¹ is an apocalyptic number.

It is an amenable number.

743581 is a deficient number, since it is larger than the sum of its proper divisors (2271).

743581 is a wasteful number, since it uses less digits than its factorization.

743581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2270.

The product of its digits is 3360, while the sum is 28.

The square root of 743581 is about 862.3114286614. The cubic root of 743581 is about 90.5960844729.

It can be divided in two parts, 74 and 3581, that added together give a triangular number (3655 = T₈₅).

The spelling of 743581 in words is "seven hundred forty-three thousand, five hundred eighty-one".