266399220 has 96 divisors (see below), whose sum is σ = 775797120. Its totient is φ = 68221440.

The previous prime is 266399201. The next prime is 266399267. The reversal of 266399220 is 22993662.

It is a congruent number.

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, 492150 + ... + 492690.

It is an arithmetic number, because the mean of its divisors is an integer number (8081220).

Almost surely, 2^266399220 is an apocalyptic number.

266399220 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 266399220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (387898560).

266399220 is an abundant number, since it is smaller than the sum of its proper divisors (509397900).

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

266399220 is a wasteful number, since it uses less digits than its factorization.

266399220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 266399220 is about 16321.7407159898. The cubic root of 266399220 is about 643.4443369956. Note that the first 3 decimals are identical.

The spelling of 266399220 in words is "two hundred sixty-six million, three hundred ninety-nine thousand, two hundred twenty".