20856474271 has 4 divisors (see below), whose sum is σ = 21142179472. Its totient is φ = 20570769072.

The previous prime is 20856474253. The next prime is 20856474281. The reversal of 20856474271 is 17247465802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20856474271 - 2¹⁷ = 20856343199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20856474281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142852491 + ... + 142852636.

It is an arithmetic number, because the mean of its divisors is an integer number (5285544868).

Almost surely, 2^20856474271 is an apocalyptic number.

20856474271 is a deficient number, since it is larger than the sum of its proper divisors (285705201).

20856474271 is an equidigital number, since it uses as much as digits as its factorization.

20856474271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285705200.

The product of its (nonzero) digits is 752640, while the sum is 46.

The spelling of 20856474271 in words is "twenty billion, eight hundred fifty-six million, four hundred seventy-four thousand, two hundred seventy-one".