1531666013 has 4 divisors (see below), whose sum is σ = 1532267580. Its totient is φ = 1531064448.

The previous prime is 1531666007. The next prime is 1531666021. The reversal of 1531666013 is 3106661351.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3106661351 = 241 ⋅12890711.

It can be written as a sum of positive squares in 2 ways, for example, as 1180403449 + 351262564 = 34357^2 + 18742^2 .

It is a cyclic number.

It is not a de Polignac number, because 1531666013 - 2⁸ = 1531665757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531666613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296948 + ... + 302061.

It is an arithmetic number, because the mean of its divisors is an integer number (383066895).

Almost surely, 2^1531666013 is an apocalyptic number.

It is an amenable number.

1531666013 is a deficient number, since it is larger than the sum of its proper divisors (601567).

1531666013 is an equidigital number, since it uses as much as digits as its factorization.

1531666013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601566.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 1531666013 is about 39136.5048643846. The cubic root of 1531666013 is about 1152.7134445936.

The spelling of 1531666013 in words is "one billion, five hundred thirty-one million, six hundred sixty-six thousand, thirteen".