20515212525253 has 4 divisors (see below), whose sum is σ = 20524848606540. Its totient is φ = 20505576443968.

The previous prime is 20515212525209. The next prime is 20515212525257. The reversal of 20515212525253 is 35252521251502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10603085912644 + 9912126612609 = 3256238^2 + 3148353^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20515212525253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20515212525257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4818037450 + ... + 4818041707.

It is an arithmetic number, because the mean of its divisors is an integer number (5131212151635).

Almost surely, 2^{20515212525253} is an apocalyptic number.

It is an amenable number.

20515212525253 is a deficient number, since it is larger than the sum of its proper divisors (9636081287).

20515212525253 is an equidigital number, since it uses as much as digits as its factorization.

20515212525253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9636081286.

The product of its (nonzero) digits is 300000, while the sum is 40.

Adding to 20515212525253 its reverse (35252521251502), we get a palindrome (55767733776755).

The spelling of 20515212525253 in words is "twenty trillion, five hundred fifteen billion, two hundred twelve million, five hundred twenty-five thousand, two hundred fifty-three".