20857945017 has 48 divisors (see below), whose sum is σ = 34771873920. Its totient is φ = 10888390656.

The previous prime is 20857945013. The next prime is 20857945033. The reversal of 20857945017 is 71054975802.

It is not a de Polignac number, because 20857945017 - 2² = 20857945013 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20857945013) by changing a digit.

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 in 47 ways as a sum of consecutive naturals, for example, 313959 + ... + 374547.

It is an arithmetic number, because the mean of its divisors is an integer number (724414040).

Almost surely, 2^20857945017 is an apocalyptic number.

It is an amenable number.

20857945017 is a deficient number, since it is larger than the sum of its proper divisors (13913928903).

20857945017 is a wasteful number, since it uses less digits than its factorization.

20857945017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60722 (or 60709 counting only the distinct ones).

The product of its (nonzero) digits is 705600, while the sum is 48.

The spelling of 20857945017 in words is "twenty billion, eight hundred fifty-seven million, nine hundred forty-five thousand, seventeen".