20556174671 has 2 divisors, whose sum is σ = 20556174672. Its totient is φ = 20556174670.

The previous prime is 20556174649. The next prime is 20556174673. The reversal of 20556174671 is 17647165502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20556174671 - 2¹⁰ = 20556173647 is a prime.

Together with 20556174673, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20556174673) 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 as a sum of consecutive naturals, namely, 10278087335 + 10278087336.

It is an arithmetic number, because the mean of its divisors is an integer number (10278087336).

Almost surely, 2^20556174671 is an apocalyptic number.

20556174671 is a deficient number, since it is larger than the sum of its proper divisors (1).

20556174671 is an equidigital number, since it uses as much as digits as its factorization.

20556174671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 352800, while the sum is 44.

The spelling of 20556174671 in words is "twenty billion, five hundred fifty-six million, one hundred seventy-four thousand, six hundred seventy-one".