20081513 has 4 divisors (see below), whose sum is σ = 20571348. Its totient is φ = 19591680.

The previous prime is 20081483. The next prime is 20081519. The reversal of 20081513 is 31518002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31518002 = 2 ⋅15759001.

It can be written as a sum of positive squares in 2 ways, for example, as 6744409 + 13337104 = 2597^2 + 3652^2 .

It is a cyclic number.

It is not a de Polignac number, because 20081513 - 2⁶ = 20081449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20081519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244856 + ... + 244937.

It is an arithmetic number, because the mean of its divisors is an integer number (5142837).

Almost surely, 2^20081513 is an apocalyptic number.

It is an amenable number.

20081513 is a deficient number, since it is larger than the sum of its proper divisors (489835).

20081513 is an equidigital number, since it uses as much as digits as its factorization.

20081513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489834.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 20081513 is about 4481.2401185386. The cubic root of 20081513 is about 271.8100290074.

Adding to 20081513 its reverse (31518002), we get a palindrome (51599515).

The spelling of 20081513 in words is "twenty million, eighty-one thousand, five hundred thirteen".