20857871854 has 4 divisors (see below), whose sum is σ = 31286807784. Its totient is φ = 10428935926.

The previous prime is 20857871831. The next prime is 20857871873. The reversal of 20857871854 is 45817875802.

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

It is a junction number, because it is equal to n+sod(n) for n = 20857871795 and 20857871804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5214467962 + ... + 5214467965.

It is an arithmetic number, because the mean of its divisors is an integer number (7821701946).

Almost surely, 2^20857871854 is an apocalyptic number.

20857871854 is a deficient number, since it is larger than the sum of its proper divisors (10428935930).

20857871854 is a wasteful number, since it uses less digits than its factorization.

20857871854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10428935929.

The product of its (nonzero) digits is 5017600, while the sum is 55.

The spelling of 20857871854 in words is "twenty billion, eight hundred fifty-seven million, eight hundred seventy-one thousand, eight hundred fifty-four".