266408640 has 84 divisors (see below), whose sum is σ = 916344624. Its totient is φ = 71041536.

The previous prime is 266408627. The next prime is 266408641. The reversal of 266408640 is 46804662.

It is a happy number.

266408640 is a `hidden beast` number, since 2 + 6 + 6 + 4 + 0 + 8 + 640 = 666.

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 = 266408595 and 266408604.

It is not an unprimeable number, because it can be changed into a prime (266408641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43372 + ... + 49131.

Almost surely, 2^266408640 is an apocalyptic number.

266408640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

266408640 is an abundant number, since it is smaller than the sum of its proper divisors (649935984).

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

266408640 is a wasteful number, since it uses less digits than its factorization.

266408640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92526 (or 92513 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 266408640 is about 16322.0292856005. The cubic root of 266408640 is about 643.4519210696.

The spelling of 266408640 in words is "two hundred sixty-six million, four hundred eight thousand, six hundred forty".