16505220117777 has 8 divisors (see below), whose sum is σ = 22008067950816. Its totient is φ = 11002926181632.

The previous prime is 16505220117761. The next prime is 16505220117877. The reversal of 16505220117777 is 77771102250561.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16505220117777 - 2⁴ = 16505220117761 is a prime.

It is a super-2 number, since 2×16505220117777² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16505220117277) 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, 138404688 + ... + 138523889.

It is an arithmetic number, because the mean of its divisors is an integer number (2751008493852).

Almost surely, 2^{16505220117777} is an apocalyptic number.

It is an amenable number.

16505220117777 is a deficient number, since it is larger than the sum of its proper divisors (5502847833039).

16505220117777 is a wasteful number, since it uses less digits than its factorization.

16505220117777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276948447.

The product of its (nonzero) digits is 1440600, while the sum is 51.

The spelling of 16505220117777 in words is "sixteen trillion, five hundred five billion, two hundred twenty million, one hundred seventeen thousand, seven hundred seventy-seven".