1531531 has 4 divisors (see below), whose sum is σ = 1567192. Its totient is φ = 1495872.

The previous prime is 1531499. The next prime is 1531549. The reversal of 1531531 is 1351351.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1351351 = 37 ⋅36523.

It is a cyclic number.

It is not a de Polignac number, because 1531531 - 2⁵ = 1531499 is a prime.

It is a super-2 number, since 2×1531531² = 4691174407922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1531499 and 1531508.

It is not an unprimeable number, because it can be changed into a prime (1531561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17766 + ... + 17851.

It is an arithmetic number, because the mean of its divisors is an integer number (391798).

2^1531531 is an apocalyptic number.

1531531 is the 715-th hex number.

1531531 is a deficient number, since it is larger than the sum of its proper divisors (35661).

1531531 is an equidigital number, since it uses as much as digits as its factorization.

1531531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35660.

The product of its digits is 225, while the sum is 19.

The square root of 1531531 is about 1237.5504030140. The cubic root of 1531531 is about 115.2679573878.

Adding to 1531531 its reverse (1351351), we get a palindrome (2882882).

The spelling of 1531531 in words is "one million, five hundred thirty-one thousand, five hundred thirty-one".