1231543 has 4 divisors (see below), whose sum is σ = 1274040. Its totient is φ = 1189048.

The previous prime is 1231513. The next prime is 1231547. The reversal of 1231543 is 3451321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1231543 - 2⁵ = 1231511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21205 + ... + 21262.

It is an arithmetic number, because the mean of its divisors is an integer number (318510).

2^1231543 is an apocalyptic number.

1231543 is a deficient number, since it is larger than the sum of its proper divisors (42497).

1231543 is an equidigital number, since it uses as much as digits as its factorization.

1231543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42496.

The product of its digits is 360, while the sum is 19.

The square root of 1231543 is about 1109.7490707363. The cubic root of 1231543 is about 107.1889113335.

Adding to 1231543 its reverse (3451321), we get a palindrome (4682864).

The spelling of 1231543 in words is "one million, two hundred thirty-one thousand, five hundred forty-three".