266489640 has 96 divisors (see below), whose sum is σ = 894067200. Its totient is φ = 68768640.

The previous prime is 266489623. The next prime is 266489669. The reversal of 266489640 is 46984662.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 780 + ... + 23099.

It is an arithmetic number, because the mean of its divisors is an integer number (9313200).

Almost surely, 2^266489640 is an apocalyptic number.

266489640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 266489640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (447033600).

266489640 is an abundant number, since it is smaller than the sum of its proper divisors (627577560).

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

266489640 is a wasteful number, since it uses less digits than its factorization.

266489640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23927 (or 23920 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 266489640 is about 16324.5104061347. The cubic root of 266489640 is about 643.5171270683.

The spelling of 266489640 in words is "two hundred sixty-six million, four hundred eighty-nine thousand, six hundred forty".