205506871669 has 4 divisors (see below), whose sum is σ = 224189314560. Its totient is φ = 186824428780.

The previous prime is 205506871663. The next prime is 205506871697. The reversal of 205506871669 is 966178605502.

205506871669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is not a de Polignac number, because 205506871669 - 2⁷ = 205506871541 is a prime.

It is a super-2 number, since 2×205506871669² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205506871663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9341221429 + ... + 9341221450.

It is an arithmetic number, because the mean of its divisors is an integer number (56047328640).

Almost surely, 2^205506871669 is an apocalyptic number.

It is an amenable number.

205506871669 is a deficient number, since it is larger than the sum of its proper divisors (18682442891).

205506871669 is a wasteful number, since it uses less digits than its factorization.

205506871669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18682442890.

The product of its (nonzero) digits is 5443200, while the sum is 55.

The spelling of 205506871669 in words is "two hundred five billion, five hundred six million, eight hundred seventy-one thousand, six hundred sixty-nine".