205687155071 has 2 divisors, whose sum is σ = 205687155072. Its totient is φ = 205687155070.

The previous prime is 205687155067. The next prime is 205687155133. The reversal of 205687155071 is 170551786502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205687155071 - 2² = 205687155067 is a prime.

It is a super-2 number, since 2×205687155071² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205687155671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102843577535 + 102843577536.

It is an arithmetic number, because the mean of its divisors is an integer number (102843577536).

Almost surely, 2^205687155071 is an apocalyptic number.

205687155071 is a deficient number, since it is larger than the sum of its proper divisors (1).

205687155071 is an equidigital number, since it uses as much as digits as its factorization.

205687155071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588000, while the sum is 47.

The spelling of 205687155071 in words is "two hundred five billion, six hundred eighty-seven million, one hundred fifty-five thousand, seventy-one".