205778741213 has 4 divisors (see below), whose sum is σ = 205810557660. Its totient is φ = 205746924768.

The previous prime is 205778741141. The next prime is 205778741221. The reversal of 205778741213 is 312147877502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 74135309284 + 131643431929 = 272278^2 + 362827^2 .

It is a cyclic number.

It is not a de Polignac number, because 205778741213 - 2¹⁸ = 205778479069 is a prime.

It is a super-2 number, since 2×205778741213² (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 (205778741243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15898520 + ... + 15911457.

It is an arithmetic number, because the mean of its divisors is an integer number (51452639415).

Almost surely, 2^205778741213 is an apocalyptic number.

It is an amenable number.

205778741213 is a deficient number, since it is larger than the sum of its proper divisors (31816447).

205778741213 is an equidigital number, since it uses as much as digits as its factorization.

205778741213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31816446.

The product of its (nonzero) digits is 658560, while the sum is 47.

The spelling of 205778741213 in words is "two hundred five billion, seven hundred seventy-eight million, seven hundred forty-one thousand, two hundred thirteen".