1531133521 has 2 divisors, whose sum is σ = 1531133522. Its totient is φ = 1531133520.

The previous prime is 1531133497. The next prime is 1531133533. The reversal of 1531133521 is 1253311351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1009650625 + 521482896 = 31775^2 + 22836^2 .

It is a cyclic number.

It is not a de Polignac number, because 1531133521 - 2⁷ = 1531133393 is a prime.

It is not a weakly prime, because it can be changed into another prime (1531133921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765566760 + 765566761.

It is an arithmetic number, because the mean of its divisors is an integer number (765566761).

Almost surely, 2^1531133521 is an apocalyptic number.

It is an amenable number.

1531133521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531133521 is an equidigital number, since it uses as much as digits as its factorization.

1531133521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1350, while the sum is 25.

The square root of 1531133521 is about 39129.7012638737. The cubic root of 1531133521 is about 1152.5798467492.

Adding to 1531133521 its reverse (1253311351), we get a palindrome (2784444872).

The spelling of 1531133521 in words is "one billion, five hundred thirty-one million, one hundred thirty-three thousand, five hundred twenty-one".