205666206507 has 6 divisors (see below), whose sum is σ = 297073409412. Its totient is φ = 137110804332.

The previous prime is 205666206413. The next prime is 205666206521. The reversal of 205666206507 is 705602666502.

It is not a de Polignac number, because 205666206507 - 2²⁶ = 205599097643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205666206307) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11425900353 + ... + 11425900370.

It is an arithmetic number, because the mean of its divisors is an integer number (49512234902).

Almost surely, 2^205666206507 is an apocalyptic number.

205666206507 is a deficient number, since it is larger than the sum of its proper divisors (91407202905).

205666206507 is a wasteful number, since it uses less digits than its factorization.

205666206507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22851800729 (or 22851800726 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The spelling of 205666206507 in words is "two hundred five billion, six hundred sixty-six million, two hundred six thousand, five hundred seven".