1531123331 has 2 divisors, whose sum is σ = 1531123332. Its totient is φ = 1531123330.

The previous prime is 1531123291. The next prime is 1531123357. The reversal of 1531123331 is 1333211351.

It is a strong prime.

It is an emirp because it is prime and its reverse (1333211351) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1531123331 - 2⁶ = 1531123267 is a prime.

It is a super-2 number, since 2×1531123331² = 4688677309465071122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1531123297 and 1531123306.

It is not a weakly prime, because it can be changed into another prime (1531123031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765561665 + 765561666.

It is an arithmetic number, because the mean of its divisors is an integer number (765561666).

Almost surely, 2^1531123331 is an apocalyptic number.

1531123331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531123331 is an equidigital number, since it uses as much as digits as its factorization.

1531123331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 810, while the sum is 23.

The square root of 1531123331 is about 39129.5710556607. The cubic root of 1531123331 is about 1152.5772898604.

Adding to 1531123331 its reverse (1333211351), we get a palindrome (2864334682).

The spelling of 1531123331 in words is "one billion, five hundred thirty-one million, one hundred twenty-three thousand, three hundred thirty-one".