1331531 has 4 divisors (see below), whose sum is σ = 1335600. Its totient is φ = 1327464.

The previous prime is 1331527. The next prime is 1331549. The reversal of 1331531 is 1351331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1351331 = 227 ⋅5953.

It is a cyclic number.

It is not a de Polignac number, because 1331531 - 2² = 1331527 is a prime.

It is a super-2 number, since 2×1331531² = 3545949607922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1331521) 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, 1496 + ... + 2213.

It is an arithmetic number, because the mean of its divisors is an integer number (333900).

2^1331531 is an apocalyptic number.

1331531 is a deficient number, since it is larger than the sum of its proper divisors (4069).

1331531 is an equidigital number, since it uses as much as digits as its factorization.

1331531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4068.

The product of its digits is 135, while the sum is 17.

The square root of 1331531 is about 1153.9198412368. The cubic root of 1331531 is about 110.0146261543.

Adding to 1331531 its reverse (1351331), we get a palindrome (2682862).

The spelling of 1331531 in words is "one million, three hundred thirty-one thousand, five hundred thirty-one".