205106643 has 12 divisors (see below), whose sum is σ = 338588848. Its totient is φ = 117203760.

The previous prime is 205106623. The next prime is 205106669. The reversal of 205106643 is 346601502.

205106643 is a `hidden beast` number, since 2 + 0 + 5 + 10 + 6 + 643 = 666.

It is not a de Polignac number, because 205106643 - 2¹⁰ = 205105619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205106623) 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, 1627768 + ... + 1627893.

Almost surely, 2^205106643 is an apocalyptic number.

205106643 is a deficient number, since it is larger than the sum of its proper divisors (133482205).

205106643 is a wasteful number, since it uses less digits than its factorization.

205106643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3255674 (or 3255671 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 205106643 is about 14321.5447141710. The cubic root of 205106643 is about 589.7390812206.

The spelling of 205106643 in words is "two hundred five million, one hundred six thousand, six hundred forty-three".