21110513 has 2 divisors, whose sum is σ = 21110514. Its totient is φ = 21110512.

The previous prime is 21110503. The next prime is 21110543. The reversal of 21110513 is 31501112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13454224 + 7656289 = 3668^2 + 2767^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110513 - 2⁴ = 21110497 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21110503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555256 + 10555257.

It is an arithmetic number, because the mean of its divisors is an integer number (10555257).

Almost surely, 2^21110513 is an apocalyptic number.

It is an amenable number.

21110513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110513 is an equidigital number, since it uses as much as digits as its factorization.

21110513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 21110513 is about 4594.6178295915. The cubic root of 21110513 is about 276.3755346273.

Adding to 21110513 its reverse (31501112), we get a palindrome (52611625).

The spelling of 21110513 in words is "twenty-one million, one hundred ten thousand, five hundred thirteen".