1528181813 has 4 divisors (see below), whose sum is σ = 1543312428. Its totient is φ = 1513051200.

The previous prime is 1528181779. The next prime is 1528181839. The reversal of 1528181813 is 3181818251.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3181818251 = 101 ⋅31503151.

It can be written as a sum of positive squares in 2 ways, for example, as 614147524 + 914034289 = 24782^2 + 30233^2 .

It is a cyclic number.

It is not a de Polignac number, because 1528181813 - 2¹⁶ = 1528116277 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1528181843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7565156 + ... + 7565357.

It is an arithmetic number, because the mean of its divisors is an integer number (385828107).

Almost surely, 2^1528181813 is an apocalyptic number.

It is an amenable number.

1528181813 is a deficient number, since it is larger than the sum of its proper divisors (15130615).

1528181813 is a wasteful number, since it uses less digits than its factorization.

1528181813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15130614.

The product of its digits is 15360, while the sum is 38.

The square root of 1528181813 is about 39091.9660927920. The cubic root of 1528181813 is about 1151.8387253034.

The spelling of 1528181813 in words is "one billion, five hundred twenty-eight million, one hundred eighty-one thousand, eight hundred thirteen".