205623666 has 12 divisors (see below), whose sum is σ = 445517982. Its totient is φ = 68541216.

The previous prime is 205623661. The next prime is 205623697. The reversal of 205623666 is 666326502.

It can be written as a sum of positive squares in only one way, i.e., 127035441 + 78588225 = 11271^2 + 8865^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 205623666.

It is not an unprimeable number, because it can be changed into a prime (205623661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5711751 + ... + 5711786.

Almost surely, 2^205623666 is an apocalyptic number.

205623666 is an abundant number, since it is smaller than the sum of its proper divisors (239894316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205623666 is a wasteful number, since it uses less digits than its factorization.

205623666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11423545 (or 11423542 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 205623666 is about 14339.5838851760. The cubic root of 205623666 is about 590.2341941091.

The spelling of 205623666 in words is "two hundred five million, six hundred twenty-three thousand, six hundred sixty-six".