205977588397 has 12 divisors (see below), whose sum is σ = 243534562716. Its totient is φ = 173657917440.

The previous prime is 205977588389. The next prime is 205977588403. The reversal of 205977588397 is 793885779502.

It can be written as a sum of positive squares in 2 ways, for example, as 103202205001 + 102775383396 = 321251^2 + 320586^2 .

It is not a de Polignac number, because 205977588397 - 2³ = 205977588389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205977588347) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34452948 + ... + 34458925.

It is an arithmetic number, because the mean of its divisors is an integer number (20294546893).

Almost surely, 2^205977588397 is an apocalyptic number.

It is an amenable number.

205977588397 is a deficient number, since it is larger than the sum of its proper divisors (37556974319).

205977588397 is an equidigital number, since it uses as much as digits as its factorization.

205977588397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68911948 (or 68911941 counting only the distinct ones).

The product of its (nonzero) digits is 266716800, while the sum is 70.

The spelling of 205977588397 in words is "two hundred five billion, nine hundred seventy-seven million, five hundred eighty-eight thousand, three hundred ninety-seven".