1231310531 has 16 divisors (see below), whose sum is σ = 1393818720. Its totient is φ = 1077857280.

The previous prime is 1231310477. The next prime is 1231310533. The reversal of 1231310531 is 1350131321.

It is a cyclic number.

It is not a de Polignac number, because 1231310531 - 2¹⁴ = 1231294147 is a prime.

It is a super-2 number, since 2×1231310531² = 3032251247503003922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231310533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23885 + ... + 55073.

It is an arithmetic number, because the mean of its divisors is an integer number (87113670).

Almost surely, 2^1231310531 is an apocalyptic number.

1231310531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1231310531 is a deficient number, since it is larger than the sum of its proper divisors (162508189).

1231310531 is a wasteful number, since it uses less digits than its factorization.

1231310531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31334.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 1231310531 is about 35090.0346394813. The cubic root of 1231310531 is about 1071.8216649745.

Adding to 1231310531 its reverse (1350131321), we get a palindrome (2581441852).

The spelling of 1231310531 in words is "one billion, two hundred thirty-one million, three hundred ten thousand, five hundred thirty-one".