205138820385471 has 48 divisors (see below), whose sum is σ = 322092803217024. Its totient is φ = 115779341111616.

The previous prime is 205138820385427. The next prime is 205138820385479. The reversal of 205138820385471 is 174583028831502.

It is not a de Polignac number, because 205138820385471 - 2¹⁰ = 205138820384447 is a prime.

It is a super-3 number, since 3×205138820385471³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205138820385479) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44113176 + ... + 48541218.

It is an arithmetic number, because the mean of its divisors is an integer number (6710266733688).

Almost surely, 2^{205138820385471} is an apocalyptic number.

205138820385471 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

205138820385471 is a deficient number, since it is larger than the sum of its proper divisors (116953982831553).

205138820385471 is a wasteful number, since it uses less digits than its factorization.

205138820385471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4431940 (or 4431933 counting only the distinct ones).

The product of its (nonzero) digits is 12902400, while the sum is 57.

The spelling of 205138820385471 in words is "two hundred five trillion, one hundred thirty-eight billion, eight hundred twenty million, three hundred eighty-five thousand, four hundred seventy-one".