20857680551 has 2 divisors, whose sum is σ = 20857680552. Its totient is φ = 20857680550.

The previous prime is 20857680497. The next prime is 20857680563. The reversal of 20857680551 is 15508675802.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20857680551 - 2¹⁰ = 20857679527 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20857680496 and 20857680505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20857683551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10428840275 + 10428840276.

It is an arithmetic number, because the mean of its divisors is an integer number (10428840276).

Almost surely, 2^20857680551 is an apocalyptic number.

20857680551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20857680551 is an equidigital number, since it uses as much as digits as its factorization.

20857680551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672000, while the sum is 47.

The spelling of 20857680551 in words is "twenty billion, eight hundred fifty-seven million, six hundred eighty thousand, five hundred fifty-one".