20857680563 has 2 divisors, whose sum is σ = 20857680564. Its totient is φ = 20857680562.

The previous prime is 20857680551. The next prime is 20857680583. The reversal of 20857680563 is 36508675802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20857680563 - 2²⁶ = 20790571699 is a prime.

It is not a weakly prime, because it can be changed into another prime (20857680583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10428840281 + 10428840282.

It is an arithmetic number, because the mean of its divisors is an integer number (10428840282).

Almost surely, 2^20857680563 is an apocalyptic number.

20857680563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20857680563 is an equidigital number, since it uses as much as digits as its factorization.

20857680563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2419200, while the sum is 50.

The spelling of 20857680563 in words is "twenty billion, eight hundred fifty-seven million, six hundred eighty thousand, five hundred sixty-three".