1131631531 has 2 divisors, whose sum is σ = 1131631532. Its totient is φ = 1131631530.

The previous prime is 1131631519. The next prime is 1131631561. The reversal of 1131631531 is 1351361311.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1131631531 - 2⁵ = 1131631499 is a prime.

It is a super-2 number, since 2×1131631531² = 2561179843906807922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1131631496 and 1131631505.

It is not a weakly prime, because it can be changed into another prime (1131631511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565815765 + 565815766.

It is an arithmetic number, because the mean of its divisors is an integer number (565815766).

Almost surely, 2^1131631531 is an apocalyptic number.

1131631531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131631531 is an equidigital number, since it uses as much as digits as its factorization.

1131631531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 25.

The square root of 1131631531 is about 33639.7314347187. The cubic root of 1131631531 is about 1042.0814855540.

Adding to 1131631531 its reverse (1351361311), we get a palindrome (2482992842).

The spelling of 1131631531 in words is "one billion, one hundred thirty-one million, six hundred thirty-one thousand, five hundred thirty-one".