20857871834 has 16 divisors (see below), whose sum is σ = 31469343048. Its totient is φ = 10368171072.

The previous prime is 20857871831. The next prime is 20857871873. The reversal of 20857871834 is 43817875802.

It can be written as a sum of positive squares in 4 ways, for example, as 20202358225 + 655513609 = 142135^2 + 25603^2 .

It is not an unprimeable number, because it can be changed into a prime (20857871831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521684 + ... + 560240.

Almost surely, 2^20857871834 is an apocalyptic number.

20857871834 is a deficient number, since it is larger than the sum of its proper divisors (10611471214).

20857871834 is a wasteful number, since it uses less digits than its factorization.

20857871834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40129.

The product of its (nonzero) digits is 3010560, while the sum is 53.

The spelling of 20857871834 in words is "twenty billion, eight hundred fifty-seven million, eight hundred seventy-one thousand, eight hundred thirty-four".