205598642 has 6 divisors (see below), whose sum is σ = 308428383. Its totient is φ = 102789182.

The previous prime is 205598623. The next prime is 205598647. The reversal of 205598642 is 246895502.

It can be written as a sum of positive squares in only one way, i.e., 102799321 + 102799321 = 10139^2 + 10139^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=10139.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205598642.

It is not an unprimeable number, because it can be changed into a prime (205598647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 15209 + ... + 25347.

Almost surely, 2^205598642 is an apocalyptic number.

205598642 is a deficient number, since it is larger than the sum of its proper divisors (102829741).

205598642 is an frugal number, since it uses more digits than its factorization.

205598642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20280 (or 10141 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 205598642 is about 14338.7113089008. The cubic root of 205598642 is about 590.2102496869.

The spelling of 205598642 in words is "two hundred five million, five hundred ninety-eight thousand, six hundred forty-two".