266243641989920 has 576 divisors, whose sum is σ = 759734491944960. Its totient is φ = 87821372620800.

The previous prime is 266243641989893. The next prime is 266243641989959. The reversal of 266243641989920 is 29989146342662.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 33791548541 + ... + 33791556419.

It is an arithmetic number, because the mean of its divisors is an integer number (1318983492960).

Almost surely, 2^{266243641989920} is an apocalyptic number.

266243641989920 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 266243641989920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (379867245972480).

266243641989920 is an abundant number, since it is smaller than the sum of its proper divisors (493490849955040).

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

266243641989920 is a wasteful number, since it uses less digits than its factorization.

266243641989920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8737 (or 8722 counting only the distinct ones).

The product of its (nonzero) digits is 483729408, while the sum is 71.

The spelling of 266243641989920 in words is "two hundred sixty-six trillion, two hundred forty-three billion, six hundred forty-one million, nine hundred eighty-nine thousand, nine hundred twenty".