205866375625 has 15 divisors (see below), whose sum is σ = 257264798131. Its totient is φ = 164684026000.

The previous prime is 205866375623. The next prime is 205866375703. The reversal of 205866375625 is 526573668502.

It is a happy number.

The square root of 205866375625 is 453725.

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

It can be written as a sum of positive squares in 7 ways, for example, as 190142218809 + 15724156816 = 436053^2 + 125396^2 .

It is not a de Polignac number, because 205866375625 - 2¹ = 205866375623 is a prime.

It is a super-2 number, since 2×205866375625² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205866375623) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 11334051 + ... + 11352199.

Almost surely, 2^205866375625 is an apocalyptic number.

205866375625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

205866375625 is the 453725-th square number.

205866375625 is the 226863-rd centered octagonal number.

It is an amenable number.

205866375625 is a deficient number, since it is larger than the sum of its proper divisors (51398422506).

205866375625 is an frugal number, since it uses more digits than its factorization.

205866375625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36318 (or 18154 counting only the distinct ones).

The product of its (nonzero) digits is 18144000, while the sum is 55.

The spelling of 205866375625 in words is "two hundred five billion, eight hundred sixty-six million, three hundred seventy-five thousand, six hundred twenty-five".