20513123345265 has 96 divisors (see below), whose sum is σ = 34811118607104. Its totient is φ = 10311987248640.

The previous prime is 20513123345261. The next prime is 20513123345279. The reversal of 20513123345265 is 56254332131502.

It is not a de Polignac number, because 20513123345265 - 2² = 20513123345261 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20513123345261) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1246762779 + ... + 1246779231.

It is an arithmetic number, because the mean of its divisors is an integer number (362615818824).

Almost surely, 2^{20513123345265} is an apocalyptic number.

It is an amenable number.

20513123345265 is a deficient number, since it is larger than the sum of its proper divisors (14297995261839).

20513123345265 is a wasteful number, since it uses less digits than its factorization.

20513123345265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18791 (or 18768 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 42.

Adding to 20513123345265 its reverse (56254332131502), we get a palindrome (76767455476767).

The spelling of 20513123345265 in words is "twenty trillion, five hundred thirteen billion, one hundred twenty-three million, three hundred forty-five thousand, two hundred sixty-five".