205138656 has 288 divisors, whose sum is σ = 669247488. Its totient is φ = 61585920.

The previous prime is 205138651. The next prime is 205138697. The reversal of 205138656 is 656831502.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 205138656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205138651) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5544270 + ... + 5544306.

It is an arithmetic number, because the mean of its divisors is an integer number (2323776).

Almost surely, 2^205138656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205138656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334623744).

205138656 is an abundant number, since it is smaller than the sum of its proper divisors (464108832).

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

205138656 is a wasteful number, since it uses less digits than its factorization.

205138656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 205138656 is about 14322.6623223478. The cubic root of 205138656 is about 589.7697617400.

The spelling of 205138656 in words is "two hundred five million, one hundred thirty-eight thousand, six hundred fifty-six".