266421440 has 112 divisors (see below), whose sum is σ = 663634944. Its totient is φ = 101760000.

The previous prime is 266421437. The next prime is 266421481. The reversal of 266421440 is 44124662.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1061315 + ... + 1061565.

It is an arithmetic number, because the mean of its divisors is an integer number (5925312).

Almost surely, 2^266421440 is an apocalyptic number.

266421440 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 266421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331817472).

266421440 is an abundant number, since it is smaller than the sum of its proper divisors (397213504).

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

266421440 is a wasteful number, since it uses less digits than its factorization.

266421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

The square root of 266421440 is about 16322.4213889974. The cubic root of 266421440 is about 643.4622261066.

It can be divided in two parts, 26642 and 1440, that added together give a palindrome (28082).

The spelling of 266421440 in words is "two hundred sixty-six million, four hundred twenty-one thousand, four hundred forty".