1243531 has 4 divisors (see below), whose sum is σ = 1309000. Its totient is φ = 1178064.

The previous prime is 1243523. The next prime is 1243537. The reversal of 1243531 is 1353421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1353421 = 17 ⋅79613.

It is a cyclic number.

It is not a de Polignac number, because 1243531 - 2³ = 1243523 is a prime.

It is a super-2 number, since 2×1243531² = 3092738695922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 65449 = 1243531 / (1 + 2 + 4 + 3 + 5 + 3 + 1).

It is a Duffinian number.

1243531 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1243499 and 1243508.

It is not an unprimeable number, because it can be changed into a prime (1243537) 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, 32706 + ... + 32743.

It is an arithmetic number, because the mean of its divisors is an integer number (327250).

2^1243531 is an apocalyptic number.

1243531 is a deficient number, since it is larger than the sum of its proper divisors (65469).

1243531 is an equidigital number, since it uses as much as digits as its factorization.

1243531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65468.

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

The square root of 1243531 is about 1115.1372112884. The cubic root of 1243531 is about 107.5355858390.

Adding to 1243531 its reverse (1353421), we get a palindrome (2596952).

It can be divided in two parts, 124 and 3531, that added together give a triangular number (3655 = T₈₅).

The spelling of 1243531 in words is "one million, two hundred forty-three thousand, five hundred thirty-one".