20123513 has 2 divisors, whose sum is σ = 20123514. Its totient is φ = 20123512.

The previous prime is 20123507. The next prime is 20123539. The reversal of 20123513 is 31532102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18593344 + 1530169 = 4312^2 + 1237^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20123513 is a prime.

It is a super-2 number, since 2×20123513² = 809911550922338, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20123491 and 20123500.

It is not a weakly prime, because it can be changed into another prime (20123573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10061756 + 10061757.

It is an arithmetic number, because the mean of its divisors is an integer number (10061757).

Almost surely, 2^20123513 is an apocalyptic number.

It is an amenable number.

20123513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20123513 is an equidigital number, since it uses as much as digits as its factorization.

20123513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 20123513 is about 4485.9238736296. The cubic root of 20123513 is about 271.9993917590. Note that the first 3 decimals are identical.

Adding to 20123513 its reverse (31532102), we get a palindrome (51655615).

The spelling of 20123513 in words is "twenty million, one hundred twenty-three thousand, five hundred thirteen".