266444640 has 576 divisors, whose sum is σ = 1188794880. Its totient is φ = 54743040.

The previous prime is 266444617. The next prime is 266444683. The reversal of 266444640 is 46444662.

It is a happy number.

266444640 is a `hidden beast` number, since 2 + 6 + 6 + 4 + 4 + 4 + 640 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a junction number, because it is equal to n+sod(n) for n = 266444595 and 266444604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2993716 + ... + 2993804.

It is an arithmetic number, because the mean of its divisors is an integer number (2063880).

Almost surely, 2^266444640 is an apocalyptic number.

266444640 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 266444640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (594397440).

266444640 is an abundant number, since it is smaller than the sum of its proper divisors (922350240).

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

266444640 is a wasteful number, since it uses less digits than its factorization.

266444640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The square root of 266444640 is about 16323.1320523973. The cubic root of 266444640 is about 643.4809031449.

The spelling of 266444640 in words is "two hundred sixty-six million, four hundred forty-four thousand, six hundred forty".