20173117777 has 4 divisors (see below), whose sum is σ = 20361651696. Its totient is φ = 19984583860.

The previous prime is 20173117747. The next prime is 20173117799. The reversal of 20173117777 is 77771137102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77771137102 = 2 ⋅38885568551.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20173117777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20173117747) 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, 94266799 + ... + 94267012.

It is an arithmetic number, because the mean of its divisors is an integer number (5090412924).

Almost surely, 2^20173117777 is an apocalyptic number.

It is an amenable number.

20173117777 is a deficient number, since it is larger than the sum of its proper divisors (188533919).

20173117777 is a wasteful number, since it uses less digits than its factorization.

20173117777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188533918.

The product of its (nonzero) digits is 100842, while the sum is 43.

The spelling of 20173117777 in words is "twenty billion, one hundred seventy-three million, one hundred seventeen thousand, seven hundred seventy-seven".