20542513 has 2 divisors, whose sum is σ = 20542514. Its totient is φ = 20542512.

The previous prime is 20542507. The next prime is 20542531. The reversal of 20542513 is 31524502.

Together with next prime (20542531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11343424 + 9199089 = 3368^2 + 3033^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20542513 is a prime.

It is not a weakly prime, because it can be changed into another prime (20542573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10271256 + 10271257.

It is an arithmetic number, because the mean of its divisors is an integer number (10271257).

Almost surely, 2^20542513 is an apocalyptic number.

It is an amenable number.

20542513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20542513 is an equidigital number, since it uses as much as digits as its factorization.

20542513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20542513 is about 4532.3849130452. The cubic root of 20542513 is about 273.8742429991.

The spelling of 20542513 in words is "twenty million, five hundred forty-two thousand, five hundred thirteen".