20515361 has 2 divisors, whose sum is σ = 20515362. Its totient is φ = 20515360.

The previous prime is 20515357. The next prime is 20515367. The reversal of 20515361 is 16351502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11182336 + 9333025 = 3344^2 + 3055^2 .

It is a cyclic number.

It is not a de Polignac number, because 20515361 - 2² = 20515357 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 (20515367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10257680 + 10257681.

It is an arithmetic number, because the mean of its divisors is an integer number (10257681).

Almost surely, 2^20515361 is an apocalyptic number.

It is an amenable number.

20515361 is a deficient number, since it is larger than the sum of its proper divisors (1).

20515361 is an equidigital number, since it uses as much as digits as its factorization.

20515361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 20515361 is about 4529.3885900859. The cubic root of 20515361 is about 273.7535256665.

Adding to 20515361 its reverse (16351502), we get a palindrome (36866863).

The spelling of 20515361 in words is "twenty million, five hundred fifteen thousand, three hundred sixty-one".