205417957679 has 32 divisors (see below), whose sum is σ = 234180460800. Its totient is φ = 178470826240.

The previous prime is 205417957669. The next prime is 205417957697. The reversal of 205417957679 is 976759714502.

It is a cyclic number.

It is not a de Polignac number, because 205417957679 - 2⁴ = 205417957663 is a prime.

It is a super-2 number, since 2×205417957679² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205417957669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69186107 + ... + 69189075.

It is an arithmetic number, because the mean of its divisors is an integer number (7318139400).

Almost surely, 2^205417957679 is an apocalyptic number.

205417957679 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

205417957679 is a deficient number, since it is larger than the sum of its proper divisors (28762503121).

205417957679 is a wasteful number, since it uses less digits than its factorization.

205417957679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5143.

The product of its (nonzero) digits is 33339600, while the sum is 62.

The spelling of 205417957679 in words is "two hundred five billion, four hundred seventeen million, nine hundred fifty-seven thousand, six hundred seventy-nine".