205687131343 has 4 divisors (see below), whose sum is σ = 212322200128. Its totient is φ = 199052062560.

The previous prime is 205687131317. The next prime is 205687131359. The reversal of 205687131343 is 343131786502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205687131343 - 2¹⁷ = 205687000271 is a prime.

It is a super-2 number, since 2×205687131343² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205687131343.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205687131313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3317534346 + ... + 3317534407.

It is an arithmetic number, because the mean of its divisors is an integer number (53080550032).

Almost surely, 2^205687131343 is an apocalyptic number.

205687131343 is a deficient number, since it is larger than the sum of its proper divisors (6635068785).

205687131343 is an equidigital number, since it uses as much as digits as its factorization.

205687131343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6635068784.

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 205687131343 in words is "two hundred five billion, six hundred eighty-seven million, one hundred thirty-one thousand, three hundred forty-three".