266765503680 has 560 divisors, whose sum is σ = 1066389153984. Its totient is φ = 62808514560.

The previous prime is 266765503651. The next prime is 266765503681. The reversal of 266765503680 is 86305567662.

It is a happy number.

266765503680 is a `hidden beast` number, since 2 + 6 + 6 + 7 + 6 + 550 + 3 + 6 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (266765503681) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 7732870 + ... + 7767290.

Almost surely, 2^266765503680 is an apocalyptic number.

266765503680 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 266765503680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (533194576992).

266765503680 is an abundant number, since it is smaller than the sum of its proper divisors (799623650304).

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

266765503680 is a wasteful number, since it uses less digits than its factorization.

266765503680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34486 (or 34467 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 54.

The spelling of 266765503680 in words is "two hundred sixty-six billion, seven hundred sixty-five million, five hundred three thousand, six hundred eighty".