20867777776857 has 64 divisors (see below), whose sum is σ = 31089471528960. Its totient is φ = 12344378592000.

The previous prime is 20867777776829. The next prime is 20867777776907. The reversal of 20867777776857 is 75867777776802.

It is not a de Polignac number, because 20867777776857 - 2⁶ = 20867777776793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20867777776857.

It is not an unprimeable number, because it can be changed into a prime (20867777786857) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 171878788 + ... + 172000154.

It is an arithmetic number, because the mean of its divisors is an integer number (485772992640).

Almost surely, 2^{20867777776857} is an apocalyptic number.

It is an amenable number.

20867777776857 is a deficient number, since it is larger than the sum of its proper divisors (10221693752103).

20867777776857 is a wasteful number, since it uses less digits than its factorization.

20867777776857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122214.

The product of its (nonzero) digits is 18974430720, while the sum is 84.

Subtracting 20867777776857 from its reverse (75867777776802), we obtain a palindrome (54999999999945).

The spelling of 20867777776857 in words is "twenty trillion, eight hundred sixty-seven billion, seven hundred seventy-seven million, seven hundred seventy-six thousand, eight hundred fifty-seven".