208754868609 has 27 divisors (see below), whose sum is σ = 350781105987. Its totient is φ = 119283013584.

The previous prime is 208754868583. The next prime is 208754868643. The reversal of 208754868609 is 906868457802.

The square root of 208754868609 is 456897.

It is a perfect power (a square), and thus also a powerful number.

208754868609 is a `hidden beast` number, since 2 + 0 + 8 + 7 + 548 + 6 + 86 + 0 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 192172640625 + 16582227984 = 438375^2 + 128772^2 .

It is not a de Polignac number, because 208754868609 - 2²¹ = 208752771457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (208754868659) 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 26 ways as a sum of consecutive naturals, for example, 9583959 + ... + 9605715.

Almost surely, 2^208754868609 is an apocalyptic number.

208754868609 is the 456897-th square number.

208754868609 is the 228449-th centered octagonal number.

It is an amenable number.

208754868609 is a deficient number, since it is larger than the sum of its proper divisors (142026237378).

208754868609 is an frugal number, since it uses more digits than its factorization.

208754868609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43534 (or 21767 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 63.

The spelling of 208754868609 in words is "two hundred eight billion, seven hundred fifty-four million, eight hundred sixty-eight thousand, six hundred nine".