20258856968257 has 8 divisors (see below), whose sum is σ = 21450755411496. Its totient is φ = 19066980855552.

The previous prime is 20258856968237. The next prime is 20258856968267. The reversal of 20258856968257 is 75286965885202.

It is a Cunningham number, because it is equal to 4500984²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1121303095056 + 19137553873201 = 1058916^2 + 4374649^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20258856968257 - 2¹⁵ = 20258856935489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20258856968257.

It is not an unprimeable number, because it can be changed into a prime (20258856968237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3696598 + ... + 7360879.

It is an arithmetic number, because the mean of its divisors is an integer number (2681344426437).

Almost surely, 2^{20258856968257} is an apocalyptic number.

It is an amenable number.

20258856968257 is a deficient number, since it is larger than the sum of its proper divisors (1191898443239).

20258856968257 is a wasteful number, since it uses less digits than its factorization.

20258856968257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11165267.

The product of its (nonzero) digits is 1161216000, while the sum is 73.

The spelling of 20258856968257 in words is "twenty trillion, two hundred fifty-eight billion, eight hundred fifty-six million, nine hundred sixty-eight thousand, two hundred fifty-seven".