266388303968640 has 2304 divisors, whose sum is σ = 1138780232029440. Its totient is φ = 59300746444800.

The previous prime is 266388303968621. The next prime is 266388303968669. The reversal of 266388303968640 is 46869303883662.

It is a happy number.

266388303968640 is a `hidden beast` number, since 2 + 66 + 38 + 8 + 30 + 396 + 86 + 40 = 666.

266388303968640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 137953548475 + ... + 137953550405.

It is an arithmetic number, because the mean of its divisors is an integer number (494262253485).

Almost surely, 2^{266388303968640} is an apocalyptic number.

266388303968640 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 266388303968640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (569390116014720).

266388303968640 is an abundant number, since it is smaller than the sum of its proper divisors (872391928060800).

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

266388303968640 is a wasteful number, since it uses less digits than its factorization.

266388303968640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2443 (or 2412 counting only the distinct ones).

The product of its (nonzero) digits is 1289945088, while the sum is 72.

The spelling of 266388303968640 in words is "two hundred sixty-six trillion, three hundred eighty-eight billion, three hundred three million, nine hundred sixty-eight thousand, six hundred forty".