266717640 has 128 divisors (see below), whose sum is σ = 946080000. Its totient is φ = 58856448.

The previous prime is 266717597. The next prime is 266717657. The reversal of 266717640 is 46717662.

It is a super-2 number, since 2×266717640² = 142276598974339200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18886 + ... + 29834.

It is an arithmetic number, because the mean of its divisors is an integer number (7391250).

Almost surely, 2^266717640 is an apocalyptic number.

266717640 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 266717640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (473040000).

266717640 is an abundant number, since it is smaller than the sum of its proper divisors (679362360).

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

266717640 is a wasteful number, since it uses less digits than its factorization.

266717640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10999 (or 10995 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 39.

The square root of 266717640 is about 16331.4922771926. The cubic root of 266717640 is about 643.7005989678.

The spelling of 266717640 in words is "two hundred sixty-six million, seven hundred seventeen thousand, six hundred forty".