266728644 has 108 divisors (see below), whose sum is σ = 834515136. Its totient is φ = 70334784.

The previous prime is 266728603. The next prime is 266728667. The reversal of 266728644 is 446827662.

It is a super-2 number, since 2×266728644² = 142288339060157472, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 266728644.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 39457 + ... + 45719.

It is an arithmetic number, because the mean of its divisors is an integer number (7726992).

Almost surely, 2^266728644 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 266728644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (417257568).

266728644 is an abundant number, since it is smaller than the sum of its proper divisors (567786492).

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

266728644 is a wasteful number, since it uses less digits than its factorization.

266728644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6306 (or 6288 counting only the distinct ones).

The product of its digits is 774144, while the sum is 45.

The square root of 266728644 is about 16331.8291688347. The cubic root of 266728644 is about 643.7094512556.

The spelling of 266728644 in words is "two hundred sixty-six million, seven hundred twenty-eight thousand, six hundred forty-four".